Pain in upper stomach. Little relax.

I have pain in upper mid and left side of my abdomen since last 3 month and sometimes nausea too. Did scanning, endoscopy, liver bilirubin test, kidney test, urine routine, stool test. But everything comes normal. Then started taking pantoprazole med since last 2month and also took antibiotics for amoebiasis. Little improvement but still pain comes. I tried noticing the pattern of pain coming...but there is no pattern...when I m in pain...if I lie down having face upwards, feel little relax. During sleeping time there is no pain. Sometimes feel the diaphragm and upper abdomen area too uneasy. Still taking pantoprazole... But I am in doubt if I am on correct treatment. I am maintaining my diet too. Pls advice. I have thyroid too. I am taking 125 micrograms.