It's good that you're working with your doctor to determine what might be causing the problem. The only other thing I'd suggest is taking a look at what might have changed when these headaches started (whether it's a change in routine, medical condition, etc.) Sometimes that can help pinpoint the problem.
"You may have a fresh start any moment you choose, for this thing that we call "failure" is not the falling down but the staying down." Mary Pickford
"No matter how slow you go, you are still lapping everybody on the couch."