i had this pain like yours since yesterday. Is feels like an ordinary stiff neck. I find it painful to turn my head up. Today, the pain has reduced and just felt numb when moving to the "wrong" direction. I will observe for a few days before i consult a doctor.
in 2004 i had the same & went to see doc. it took them a MRI & HEAD CT to discover that it was a bulging disc puting presure on spinal cord. be careful!!!