I also think you should at least tell your MD (if you haven't.) It sounds like a tension headache. Massaging and/or icing/heating the back of your neck should help if it is tension. Stretching neck and arms etc might help loosen some of the muscles also (but don't stretch your neck backwards towards your back!)
Cut out caffeine, drink more cool water. Try gingerale, as ginger helps with pain. (In any form... chew the root or add ground ginger to meals.)
Hope you find relief soon.