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