Why only after eating the main meal of the day, getting severe pain in upper eft abdomen? pain oes away completely after two hours or so.

See a GI doctor: Cannot diagnose over the internet, but this sounds as if it should be possible to resolve quickly with a history, physical exam and possibly endoscopy and other tests. Hope this gets better soon. Best.

Pin after meals: Most likely the culprit is the stomach itself. Either an ulcer or just hyperacidity can cause such pain which gets better once the food passes further. You should see a GI specialist who can specifically diagnose these issues. In the mean time, avoid fatty food and high calorie diet. Fruits and veggies can help.