This is funny, but that happened to me over a year ago.
I woke up and my neck was really tight. I went to work and nothing was better. I went to the nurses station and they gave me a heating pad, but that did little.
A little while later, I was in so much pain, I could not turn my head. I left work and went to the ER, big mistake, they observed me, but didn't really do much of anything. Gave me some medication for the pain and they seemed to think it was not much of anything.
The next morning, my neck was worse. I had never been in so much pain like that before. Back to the ER, they admitted me, took things more seriously. Did an MRI, couldn't find anything, they did very little to take the pain away.
The medication did very little to make me comfortable. I eventually went to a chiropractor, and unlike the ER people, he actually looked at my neck. He gave me some exercise methods to do and did some ultrasound therapy, but he admitted that there was little that could be done.
That the muscles in my neck were so raw that he did not want to adjust me. His exercises helped me, and in a day or two I was back to normal.
I never want to go through that again. I never even knew what I had. Muscle spasms?