I have a sharp pain in the back of my head, at a specific point 2-3 inches behind my left ear, which is restricting my head movements, primarily when I look up and to the left. Could this be related to TMJ? I grind my teeth (and wear a night guard) and had TMJ in my jaw once, a few years ago. This head pain is new for me and has lasted for 4 days so far. I m wondering what to do.