so hungry again and painfull !!!

i had gastric bypass 3 yrs ago and im so hungry even after a small meal,i have pain after eating,i did everthing by the book & docs orders, i excercise daily, but now im gaining lbs back is somthing wrong? my doc blames im not eating enough protene foods! gastric doc said i have a streched but anastomosis (tube under pouch) but doc wont fix it!!!
did gastric bypass fail???