You need to start what we call an "elimination diet." Tomorrow, eat only things with one in or two ingredients. Plain rice, maybe with some butter, for example. Then the next meal, you can try adding a protein like plain chicken breast, and see if that is safe, etc., etc. Then the next meal, add a veggie, etc. Soup is terribly complicated, you're gonna have to stay away from soup for the time being.

And no, anything with wheat in it is a no-go for you. There's no way to take the gluten away from already-baked bread.