nini,
I'm sorry for your pain. You need to see your doctor. Nobody can diagnose and tell you what the real problem is via the Internet. That can only be done by a doctor who can review your medical history, discuss your symptoms with you, and examine you.
Whatever the problem is, it may well be made worse by the pain medications you're taking. When taken more than two or three days a week, they can cause medication overuse headaches, aka rebound. You can read more about this in Medication Overuse Headache - When the Remedy Backfires.
Teri