The only gluten-free processed foods I buy is corn/rice pasta at Wal-Mart. If you have a BJ's close by, I justify the annual membership price by the number of gluten-free Organic rotesserie chickens I buy. Purchase 2 or 3 at a time, have one for dinner and left overs and homemade chicken soup, and 1 or 2 to shred and freeze in packages.
You can use the leftovers or frozen packages to make chicken salad with chopped chicken, celery, onion and red grapes and mayo (Hellmans is gluten-free or Spectrum has a gluten-free/Soy Free or you can make your own. Throw curry powder in there for a change, if you can tolerate it. Or just tumeric powder and a bit of sea salt.
The same salad is good with a can of tuna. If you don't want to pay for gluten-free bread, you can use it as a dip with corn tortillias or corn chips.
Chicken tacos (defrosted chicken) are great. You can use chopped raw cabbage instead of lettuce, because it is more nutritious and far cheaper. Heat up a can of Bushes black beans (they are gluten-free) and some chopped up onions and serve with Corn tortillias, and sour cream or cheese if you can do dairy. If not, guacamole or avacado slices have that nice fat. You could have that same meal with ground sirloin or ground beef or turkey or chicken.
If you live in an area that has an Indian store or Oriental store, you can buy rice in bulk very cheaply there. Rice and beans or lentils combined result in a protein combo better than each food individually. Sauteed celery and onion and/or carrot and/or chopped cabbage always works as an addition to anything for flavor. You can buy dried mushrooms pretty cheap in an oriental store, soak them, and add them to stews or soups or beans and rice.
I find that purchasing fruit and vegetables at a fruit market saves so much money, and fresh is so much better if you can find the time/energy to deal with it. I spend about $20 a week at the vegetable stand, but use almost everything and compost most of what's left over. Since you have children, you can ask your child if they'll dig a hole and bury the scraps.
My chili mix is pretty simple. It's 2 T. of chili powder. If that doesn't taste right, I add a little cayenne pepper or tabasco sauce and taste again. Cinnamin (sp?) is a nice addition too.
I sure hope you start feeling better! My heart goes out to you. I don't know if this will be any comfort, but a mother wrote an editorial in our local rag about why she can't afford to follow the recommended USDA diet because produce is so expensive. She feeds her kids fast food all of the time. I haven't responded, but I do think that you can feed a family of 4 on rice, cabbaage, carrots, onions, beans, selected on sale proteins, basic spices, fresh fruit, canned goods for less than you can consistently eating at fast food joints. And your kids will be so much healthier and learn better habits, and of course you will feel so, so much better. Your time is coming...