I Can Potatoes And Rice, With A Few Veggies. After

I can potatoes and rice, with a few veggies. after I eat for a time, intolerance builds and I cannot eat for a time. I have eaten mostly chicken for protein. Now I have reach a time when I cannot eat only small amts and for not long. I have gone thru potatoes and rice several times and they are causing headaches, stomach upset and pain. I take amitryptaline, zantac,and beno. Is there anything I can do to increase my complex carbs. I have been to gastroentrogists, nutritionist and no one has an answer.