I would be getting it checked out ASAP......I dont mean to alarm you but my sister just recently (as in just 3 weeks ago) went to hospital with a sudden onset migraine pain that wuldnt budge pretty much like you are describing...it turned out to be a brain anuerysm.....seriously I would not muck around with head pain.......it has been a real wake up call for us a family as to how quickly it can happen......