So many good suggestions, just try to treat it as a challenge and make it a positive experience rather than getting down hearted.
I have a council allotment which costs about thirty pounds a year for 265 square metres. I bought fruit trees and bushes from aldi, which I planted around the edges, which provides all the fruit I eat, berries can be frozen to go on winter porridge, and I make a years worth of jams and chutneys. A whole load of veg can be grown from cheap seed germinated on windowcills. It's hard work, but I can have heaps of lovely fresh veg, companionship of other allotment holders, also trade surplus veg and seeds with other folks on site.
If your health and mobility permit could you have a bicycle instead of a car? If you have a car get rid of it if it's not an absolute priority.
Have you a hobby that an earn you a few pounds?
My neighbour sews together others peoples finished knitted jumpers for a small charge. Also knits lovely xmas decorations and cushion covers!
Also if you live in town, take a rucksack to do your shopping, you will not spend too much if you have to carry it all on your back, back home. Or a shopping trolley thingy?
Cheap moisturiser can be upgraded by the addition of a squeeze of evening primrose oil from a broken open capsule.
Rent a room as the previous poster suggested might be a goer. I did once rent to a female student in term time, which was lovely, and I missed her when she went.
Good luck, and stay positive. Me and my fella live on about seventeen thousand a year. We have three hounds, he has a Harley, and we have a 'dog cottage' once a year out of season for a holiday with the hounds.