Babysitting a 15 month old boy driving me to distraction please help!

I understand exactly where you are coming from but you are probably experiencing a normal little boy who is still in the process of learning his boundaries. The difference between him and your daughter is that you are physically compromised and 20 years older. It makes such a difference.
I found the same with my grandson and it wasn't I couldn't cope per se, I just found that the long days were crippling. I would have him for one day from 8 to 6.30, have a day off and then do the same again. I wasn't really recovering between bouts so it was really stressful. Initially, I had to reduce to one day a week but as he got bigger and was ASD, the lockdown came and I have taken the opportunity to say to my children that I love having him but cannot do long days anymore. You have to do something to resolve this or you will end up resentful.

Get him to do 'tidy up' games. A little sponge, a duster and dust pan and brush. Maybe a reward at the end. He may not do a perfect job (!), but he may enjoy it and you will feel he's learning good habits. How about a little watering can to water every plant in the garden? That should use up some time. Most children love water play. My GC spent ages recently making water handprints on paving slabs and patio window, then soaking some old rags and learning how to squeeze them out. NB: have a change of clothes to hand. Old cardboard boxes or a box of ribbons are another time waster - I mean useful/cheap play activity! At this age, as you are finding, anything that's not a toy is far more interesting. I always had a box of 'clutter' for the kids to use their imagination. Perhaps a drawer for him to sort out thing like socks....

Oh dear . he is not far off he terrible twos.

I used to find that a very clear " that is really" naughty followed by a period of time on the "naughty step - one minute for every year of their age ( a bit longer if they are older or have been particularly naughty. If he was older I would get him to pick up the mess and put it in a waste bin. I used a kitchen timer and made sure we did something fun afterwards - a trip to the park, or a game in the garden or a game of snap, etc. Be firm but do not shout. Reward good behaviour - good colouring, etc. Take care and good luck.

I agree with @GagaJo and @Calistemon, better that he shouldn't eat the rubbish, something in them may even be what is making him ultra active. If you find something else that he likes maybe you can wean him off them? It would be great if you could find something relatively healthy that he really likes. We know a child who had literally nothing but cucumber, ham and apple juice when she was a toddler, but gradually she ate more fruit and other nutritious foods and her health did not suffer.
Or simply don't offer any of the rubbish - he'd be awful for a while but will eventually eat something else when he's really hungry.
I sympathise with you about the running around and so on, one of my boys was like that. The idea of childproofing a space in your house sounds good and would limit the mess to one room. We only ever ate at the kitchen table, with a hard floor underneath which made life much easier.

The thing is that many have missed is that your fibromyalgia means that some days are much more of a struggle for you than others and having a 15 month old hyperactive toddler will not be easy.
Put everything away that you don't want him to touch - right out of his sight in a cupboard - perhaps ask your daughter to do this with you. If there are any rooms (such as your bedroom ) that you would rather he didn't go into, see if you can either fit a bolt to the door or fitting a gate latch with a hook isn't difficult. Cupboards - tie the handles together - I know you can buy plastic cupboard locks cheaply , but if my nephew could work out how they work within 15 minutes, I'm sure your grandson will be able to.
Only give him healthy food - he won't starve if he refuses to eat apples etc the first few times but once he realises that that is all that is on offer, he'll eat it!
Only give him a drink if sitting in a highchair. If nothing else it will at least give you a chance to sit down with a cuppa yourself!
If you can take him outside, do so- he'll be quite happy with a soft ball to kick or throw and run up and down - even get him to jump up and down if you have to!
Then you can go back inside and have a quiet time where you can sit down with a book with him or even have lunch.
Maybe buy one of "Supernanny" Jo Frosts books for ideas.

My sister had fibromyalgia and found it difficult to cope with her grandson on her bad days and he was a quite a peace full little boy. He had eating problems too but she found it was easier to give him what he would eat rather than try and encourage better eating habits (She considered it a thing his mum had let him do so let his mum change the habits) Eating was always in his high chair in the kitchen (Not one for letting him wander around while eating)
She learned to pick her battles, spend a lot of time if not in the garden then at least with the back door so he could go in and out. Hope thins settle down for you as he gets older

Why has this behaviour been allowed to escalate? Does he do this same thing at home, or does he act up at your place because his home is a "prison"? Have you told his parents that you will not be able to keep him any longer, if things remain the same, not because you are not in perfect health, but because there is damage being done, not just general naughtiness? Some of us have never, ever, childproofed a room, despite having naughty children and grandchildren. Discipline includes the word "No!", not a 'naughty chair' or spankings.

never childproofed a room

Did you never move anything breakable up to a higher shelf or put locks or those child proof door catches on doors eg medicine cabinets?

Just a word of warning to the OP if she is still on here: those childproof door catches that you have to press down are not necessarily a deterrent to all toddlers, as my very determined DGS worked out how to get past them. The same DGS who worked out how to dismantle his playpen.
He wants to be an engineer.

As far as I am concerned this is normal behaviour for a boy of 15 months. You can not expect a child under three to understand that they should sit quietly.
If you are not physically capable of looking after the child then other arrangements should be made.

Cher..I do feel for you. Is it fair to you that you take care of your Grandson right now? You have Fibromyalgia & COPD...you must also be in pain as well as chronic fatigue. Your patience won't be the same. You don't say whose idea it was for you to look after your Grandson, how many days you have him in the week or how many hours in a day? I think you need to prioritise and look after you first. Otherwise you are going to knock yourself backwards with your health. I think you need to reassess how often you take care of your Grandson with your daughter...she should understand your situation.

Playpen - not all day but for periods of time to give you a chance to sit down with a cup of tea. Yes he'll probably scream while in it, but then it sounds like when he's not in it he's quite difficult too. He'd get used to it anyway, especially if there are one or two special toys that he can only play with while in there.

All is normal for a child of his age!

I never childproofed a room either Callistemon no stair gates either .My children didn't touch things or draw on walls or like my friends wee boy climb up display cabinets and topple and destroy them .The worst thing that happened was my daughter "baking" on the kitchen floor with 6 eggs and a pack of butter at 3am ,she couldn't reach the flour and came to wake me to get it for her !She was about 18 months .
Shes a fantastic cook and baker now ,though she sticks with a more normal surface .

Please don’t take this the wrong way. I do sympathise with op. I would consider myself very experienced 5 sons 7 grandsons and only one that I struggled with from day 1. Very similar problems to op and long story short he is on the spectrum. He was diagnosed at about 2/3yrs old but looking back it was obvious much earlier. There is lots of info out there about autism, and reading up about it might help understand the best way of helping both of you. He is 15 now and coping very well but the early years were difficult. A lot of people find it difficult and are in complete denial, however acceptance is the best way forward to get the help needed. Find out as much info about it as possible, before suggesting to parents because it probably won’t go down well

The trouble with a playpen in this instance is that he's not used to being in one and could see it as a prison.
I put mine in one for half an hour or so each morning from a young age, with favourite toys, while I vacuumed (we had a hairy dog). They were quite happy in there for a short while.

talk to your daughter and ask her how he behaves at home and what she does that works best .... and then come up with a strategy together.
good luck xx

paddyanne my first was a very 'Meddlesome Mattie' as my sister called her, which was a bit of a surprise after looking after sweet little nieces! However, the others weren't so meddlesome.
My 'Meddlesome Mattie' turned out to be a very adventurous young woman. She teaches children with special needs now, loves it.

I also agree about the high chair and confine food and drink to one safe area. Our local reuse and recycle group often has high chairs on offer or you can ask if anyone has one. Most areas of the country have these groups. I used to have a rest time with story books to look at and sometimes they doze off if you are on the bed !. If your health means you really cannot cope you needto let the parents know rather than endander youself or the child.

Oh I so get what you're saying. I to had three children; two girls and a boy. I find my grand-daughter very hard work. Almost exactly as you describe. She's exhausting! I certainly don't remember feeling this way with my children. I've thought about it and realise that my life is totally in order now. I don't work all that much and so this little one is quite a disruption to the peace and tranquility. And thinking more she's is very much like my eldest daughter, her mother, I've just forgotten :-)

Some really good advice here ..but quite a lot only suitable for children ..not babies .At 15 months he really is still a baby ..if he wasn't able to run & still tentavily toddled you would think so.Do as others have suggested baby proof your home ..only feed him in a highchair & water the rest of the time .Time in the bath or paddling pool ..always with him is a great idea.But if you really do dread seeing him ..be honest with his parents & maybe he could go to a Nursery where they are prepared for this normal behavior .

Summerstorm please dont stick a label on what seems to me to be absolutely normal behaviour for a 15 MONTHS old baby.
My son always had a mad half hour ,would run in circles and up and down the hall non stop ,just before bath time every night .
Out added bonus was he always stripped his clothes off too so he was a real wee comic..a naked baby whirlwind

.Many years later I met the man who had been our paperboy in a "nice" restauarnt.the first thing he said was does your boy still answer the door naked.....I laughed because I thought I was the only person who would remember it ,the answer was no but he is 24 now so I would worry if he did

Knowing something is not allowed, and having the emotional maturity not to do it, are two very different things! He's very young yet.

Cher69 well said and be kind to yourself.

There are always people in this world that think they know better, mmm balderdash!

Oh come on gransnetters! He is only 15 months old, which is a baby!! Have no expectations of the boy. He is never going to be like your daughters when they were little. I'm a mum of two girls. And my second grandson was exactly the same!! What a shock to the system. He didn't walk at 11 months, he got up and ran! Honestly, literally. At Chester zoo in a bank holiday, he kept running up to other families on the picnic lawn and trying to join in. I could go on forever.
The things about boys in general is that they are active and need to move, they don't sit down to do crafts like girls.so funny.
So play to his strengths, spend most of the time outdoors if you can, as for food, a balanced diet will come. When he is 15 probably! But don't put the lad in a position where he has the opportunity to chuck his quavers. He really is too young to understand directions, so just play to his strengths.
My chaps elder brother was much more placid, which made the dynamo more novel!
A little secret - now this boy is my secret favourite of my four grandkids, two wonderful girls and two boys.

If you don't want him getting into things then get a couple of baby gates and put them in the doorways of your ground floor rooms. Look around each room and imagine you are that age, what can you see that looks interesting? Move everything you want to keep out of his way up a level so he can't reach it, remove items like stools so he can't drag them over and use them to climb up with. Ask his parents what toys are his favourites and borrow a couple so that you know he does like playing with them. Can you take him outside at all? If you have a safe and secure garden he would probably enjoy being outside in the fresh air (and it does tire them out) When the weather is nice could you do a paddling pool outside for him? My grandson used to play for ages in his (with a few toys so he could pour the water and splash about with it) or a sand pit perhaps? . Is there a local park you could go to where he could burn off some of that energy? They are open again to the public I believe. I worked in a Day Nursery and we used to get the kiddies to do lots of different things during the day such as painting (cover a larger area than you think with newspapers to avoid splashes), active nursery rhymes (Teddy Bear, Teddy Bear, touch your toes etc), interspersed with quieter sessions of reading a book together, outdoor play and sitting down together to eat lunch (no snacks allowed) and then a jam sandwich before home time. Variety and getting out in the fresh air should help keep him busy and tire him out. I was 48 when my grandson was born and worked full time along with babysitting him one day and overnight a week. It is a shock to the system but, once you get organised and settled into a routine with him it will get easier and you will enjoy your time together so much more. Final tip - get a playpen, not for everyday use but for those time when the doorbell goes and you need to be sure he is somewhere safe. Keep a couple of toys just for the playpen so he doesn't see them everyday and he will, most likely, be happy as larry in there for a few minutes giving you the time to deal with whoever is at the door or to nip to the loo in peace!!