Don't you have a stiff neck? But if it's worsen that that, then I guess you have to see an joint pain specialist. There might be some broken veins. Try to undergo test and check ups for that matter and ask what a doctor can advice on your with this pain trouble you're suffering. I hope you'll get better soon.
Without further information, this is a very difficult question to answer.
Let me just throw out a suggestion -- try having a head and neck massage. This may be a simple matter of muscle tension. See if this eases the problem.
The other idea I have is this may be some kind of TMJ manifestation. Does your dentist tell you that you grind your teeth in your sleep? This can cause a great deal of tension in the neck and head muscles.
Try the massage and see if it helps.
If not, then you're best advised to visit your doc for a workup.
Good luck -- I hope a massage or two resolves your problem.