Yep, I too carry my tension in my neck, and get the resulting headache. I can be doing some mundane task, like peparing food, and I realize that my shoulders are nearly touching my ears! I have to consciously relax. It is as if my body's natural state is tense. Try practicing some progressive muscle relaxation. Keep up on the exercises that the doc gave you too. Also, if possible, try strenghtening the supportive muscles (traps, lats, pectorals) with light weight resistance.
"Courage is not the abscence of fear, it is feeling afraid and doing it anyway!"