Both Jordan Peterson and his daughter had some form of auto-immune problem which caused some severe problems and IIRC his daughter lost a wrist or an ankle from it. Try to find some of his early talks (a few years ago), because he gets into some detail. IIRC, again, his daughter changed her college routine/diet and discovered that wheat or gluten "allergy" or something like that seemed to be fucking her (and him) up big time and could have had genetic roots. (Allergies, or your body's reaction to chemicals, pollutants, etc., can manifest themselves in a lot more ways than a cough or skin rash, and you can be allergic to more than dust or pollen. You may not even realize what is causing your problems.) There's still alot we don't know. /In any case, their turnaround was remarkable. He lost a ton of weight and returned to excellent health. And apparently she's fine as well
Changing your diet is a great start. Read up on clearing your body of potential antigens. The theory is that you start a liquid or modified liquid diet, and for a day or two only eat/drink shit almost nobody is allergic to such. Usually restricted juices (pineapple) or just water. A fast, actually. After a day or so the hunger pangs disappear. You get weak fast, but you feel alert. Then when your system is clear, you add one food at a time - say potato. Next day pasta. etc. If you suddenly feel tired, you've hit something your system has a bad reaction to, because food shouldn't make you tired, or so the theory goes.
Good luck!