I Had Gastric Bypass Surgery 11 Years Ago And Have

I had gastric bypass surgery 11 years ago and have had problems since. I have had ulcers, recently had a balloon enlargement done. I have trouble eating anything and have a very, very restricted diet. At this point I am probably underweight. I am getting increasingly weak and shaky. I have been to several Dr's with no clear answers. I have no idea what to do at this point but need some guidance.