PLEASE HELP DIAGNOSE

I've had constant neck pain & headaches for over 6 years. It is a tight, aching, burning, strangling pain. And it is constant - it is there 24 hours a day.

I've been to over 60 doctors in almost every specialty you can think of, with no firm diagnosis and no resolution. I've tried many medications - none seem to give any real relief. I've had numerous MRIs, xrays, and cat scans - all showing that everything is aparently "normal." I've also had Botox shots in my neck and back of head, physical therapy, massage, and many types of "alternative" treatments (chiro, osteo, neuro-cranial restructuring). I've had cortisol shots in my cervical facet joints and diagnotic shots in various upper vertebrae (C1 - C4), as well an epidural in my spinal cord. I've also gone the "dental" route and have seen many dentists, tmj specialists, and orthodontists. I've been fitted with various orthodontal appliances (upper & lower splints). I've traveled out of state, across the country and even out of country, searching for anyone who can help. All of these years later, I still have no diagnosis and no relief from the constant 24/7 pain in my neck and base of head.

Please help diagnose my neck problem - is it muscular, nerve damage or something else?
Please help...