If you can eat meat and fruit, perhaps the Specific Carbohydrate Diet is what you need. It has done wonders for many! In SCD you cannot eat grains but you can eat fruit, meat, legumes, nuts, seeds, vegetables (except potato) cheese, and cultured milk like unsweetened yogurt. Perhaps grain is what you should avoid.
The SCDiet theory is that the starches in grains, potato, and milk are not properly digested and eating them causes digestive problems which can cause a lot of other problems. For some people SCDiet has worked wonders!