To get frustrated with my husband sitting in his armchair for 14 hours a day !

You don't say in your post if you've actually spoken to him about how you're feeling and your frustrations. If you've always tried to be sympathetic, perhaps he doesn't know you are in any way unhappy with things.

An honest conversation might be a good start.

Does he have a diagnosis for the dizzy spells? There can be many reasons for these. He could have been looking them up on the net and worrying about them unnecessarily. Suggest he gets himself checked out by your GP and perhaps find a remedy.

Maybe he's scared. Scared of his heart stopping. Scared of falling. Who knows.

It's a shame for you both but I don't think you should be doing anything too drastic.

All the suggestions involve the poster leaving the house and finding activities to do; all the chores remain for her to once she is home.
A showdown is called for; I would unplug the TV and confiscate the tablet for a start because I really couldn't stand television noise all day. Draw up a list of chores to be done whilst you are out: preparing a meal, using the washing machine, ironing, then supervise him hoovering and cleaning when you are home in case he does have a dizzy spell.
Sitting in a chair for 14 hours a day is not good for his health anyway.

Start by stopping the chair service. let him make his own hot drinks duringthe day, go out and buy anything he wants for himself, from the morning paper to clothes.

Get yourself some outside activity, anything from the WI, to an art class, to the local family history society. Meet friends. visit local small towns and walk round them getting to know them.

Just grab any opportunity to leave him to look after himself. Say you are tired of cooking and now want to share it 50:50, one week he does it (including shopping) one week you do it.

I very much feel your frustration but after 51 years I suspect the only change you’ll be able to make is in your own attitude! I think you will have to leave him to his own devices a bit more and go off and do things for yourself. Necessity might make him do more but even then, probably not much! Why would he change, it sounds like life is great for him but feeling like this is not going to do much for you or your health. Maybe you could start a hobby with a friend, start/join a book club or whatever interests you. Difficult at the moment I know but otherwise you risk ending up being a carer with no other outlets, which doesn’t sound like what you want. Good luck!

Maybe he’s more ill than you realise, dizzy spells are horrible and (he’s obviously had heart problems) as you can easily fall and/ or lose your confidence Presuming your husband isn’t a spring chicken if you’ve been married 51 years and maybe he has aged in a different way to you
If he’s never been very sociable or a goer outer he isn’t going to change now is he ? and you ve obviously loved him enough to have stayed for 51 years
I d let him do what chores he can sitting down…. preparing veg, folding washing, cleaning the family silver ? etc etc
As Tanith says do your own thing part of the time, meet up for a coffee with a friend, go for a walk, perhaps a bit of voluntary work to get you out the house
But he’s not going to change now if he’s always tended to be a ‘sitter’/watcher

My DH could do this all day if I let him but I make him go out every day. Some days we just go for a walk and others we go out for coffee. He always feels better for going out.

Diverticultis is no reason to spend the day in a chair ( I know, I have it), in fact it is improved by moving around, keeping the digestive system moving, sitting is not good. Why not some sort of compromise? Maybe let him sit and do what he wants for a couple of hours, then get him up and moving, maybe shoving the vacuum around, or walking to the shop to get a paper, then back into the chair? I am a lazy sod, and it is only guilt that keeps me from sitting in a chair with a good book all day!

The solution surely is to stop pandering to him. You are enabling the situation and it looks like only you will be able to alter the status quo.

Live your own life! Let him sit while you go and do ‘stuff’ without him. Either he will join you (eventually) or he will continue his sedentary life, trouble is tv and tablets can suck up a great deal of time without you realising!

That must be very frustrating, can you not get him out for a walk if he’s physically able? Fresh air and exercise with a different view would help both of you. If he really won’t move himself then get yourself out and do your own thing, when my husband was very ill, too ill to walk he would send me out to a local cafe nearby and id get a nice coffee and watch the world go by for a break.
Sorry if that sounds a bit feeble.

He's got the life of Riley, hasn't he? Waited on hand and foot, no jobs to do, I'm not surprised he doesn't leave his chair! First thing I'd do is to go out more on my own, lunch with friends and so on, telling him he'll have to get his own lunch. Find yourself too busy doing his jobs to see to him. Go to a friend's overnight - he'll soon remember what it's like to be in a partnership. Good luck