Please Help!

Hi

I am taking on a 12 on a slow night close to 20 on a regular night of feral cats 95% so far I have TNRd. Money is getting tight since I was on FMLA and trying to do catch up. I buy Friskies wet and dry food is Friskies as well. I am try to also add raw/cooked meets to supplement their diet. I need help on recommends from an experienced person to guide on preferred feral cat diet. Im thinking I can use canned, dried, and cooked meats to milk up the food since winter is coming. My feral colony has access to 5 cat house lined straw and they will have heated winter bowls. Its the cost the canned food thats killing me. I already work 2 jobs and can not add anymore hours to my week. Im in mid 50s now and I don't know if I can keep up the pace of trying to add more hours with my second job. Any advice on supplementing a diet will be greatly appreciated. When I take care of an animal issue for life.