I get that you can’t cook and in a time of financial stress “learn to cook from scratch” probably isn’t helpful, but you could probably manage basic things like:
Penne pasta with jar sauce - should be no more than £1.50 for a 500g of pasta and an own brand jar of sauce, that should make about 4 portions.
Rice, kidney beans and a jar of chilli sauce- again should be doable for under £3 to make 4 portions, you can get a kilo of white rice for £1.85 which you will only need half of, chilli sauce for £1 and kidney beans for 50p.
Own brand baked beans are cheap and all you need to do to make a baked potato is buy a big potato, put some holes in it with a fork and microwave it
Similarly you can make curry using own brand sauce, chick peas and more of the rice.
You can also buy own brand tinned soup and own brand bread and margarine.
You can get 4 bean burgers for £2.10 and 750g own brand wedges for £1.50 and a kilo of frozen peas for £1.55, again that’s a few meals.
Peanut butter you can get for £1 a tub that you can use with the bread for sandwiches, buy apples and carrots and cut into sticks.
It might not be the most exciting stuff but you should be able to manage basic meals made from jars, packets and tins, plus tea, coffee, some biscuits and a bit of fresh fruit.