Much of what you say sounds like celiac disease, or at the minimum gluten intolerance. Try omitting all gluten (wheat, barley, rye), and be STRICT about it. See how you feel. However, if you decide you want to do the blood test or biopsy for celiac disease, do NOT stop eating gluten until after you have the testing done (you need to be eating it for the testing to be accurate). But regardless of whether you get the testing done or not, if you feel better and see improvements to your health after omitting gluten, then your body is not tolerant of it and you need to totally avoid it.