Talk to General Physician on Abdominal Pain

Hi, i feel stomach cramps 2 to 3 times a day specially when i wake up in the morning,gerd,less apitite, all my cbc lft sugar thyroid vit d almost all tests are clear alhamdullilah my weight is 50kg and i dont take milk eggs etc because it worsen my symptoms I quit smoking and tea/coffee but i take a glass of coke after dinner or lunch kindly prescribe me any medicine and please elaborate and what should i eat to improve my weekness and that help me in gaining weight with disturbance thanks in advance