Questionable non-traumatic neck injury.

As I awoke yesterday, I laid supine and lifted my head from my pillow to reposition it underneath. I heard and felt a loud "pop" in the back left region of my neck that did not correlate to my neck cracking. I immediately experienced immense pain and was unable to move my head without crying. I physically could not turn my head left or tilt it left. I struggled getting out of bed due to the severity of the pain. I applied ice, took a hot shower, and applied icy hot to only get some relief. It's been a full day and I am still experiencing severe pain and immobilization on the left side of my neck. I am able to now turn my head to the left to some degree, but cannot tilt my head or surpass the minimalized turning radius without excruciating pain. Can you tell me what happened and if this may resolve itself, or if I should seek help?