Having luq pain, when bending it feels like something is being compressed and immediately feel lightheaded and nauseous. no appetite, feel full when eating a little and wake up nauseous. have had egd/colon, u/s and ct showing all normal?

This is a tough case to make the diagnosis without a direct history and physical examination because most diseases in the abdominal cavity are ruled out with all the tests you have been through. I suggest a second opinion with an experienced internist in your town and you should get your medical records before the visit. This may be very well a functional problem than a structural issue.