I thought it was my neck too, and so did the doctors until it spread to my feet. Same here with stomach sleeping and waking up with numb hands. I have always been a stomach sleeper and never had that issue. That was what happened at my onset. It crept up in such a subtle way that I thought it was just something that would go away. Then it went to my feet. Then my feet and hands would get cold and numb. I won't go into the rest of my story because don't want to alarm you. Not every case is as bad as mine was. Finally neuros in NY figured it out. Small fiber neuropathy with autonomic involvement, but they don't know how it happened. I think you should get a skin biopsy to rule out SFN if you have no deficiencies, diabetes, and the rest of your blood work is good.