I think you may have multiple food intolerances. A month after going gluten free I felt glutened, but I could not find the source. Finally figured out it was a response to soy. Via an elimination diet I found I also developed problems with dairy, eggs, corn and rice. I know the symptoms well enough now to understand when I have eaten an offending food.

The only answer in my mind is eating a very limited diet and reintroducing suspect foods every 3 days or so. You need to be suspicious of gluten, soy, eggs, dairy, peanuts, beans and nightshade vegetables.

Best of luck!