Recently I started feeling these subtle twitches or spasms (maybe even like a vibration feeling) in the back of my head/base of my head. I feel it a little during the day but mainly when I go to lay down and have my head against my pillow. It’s not constant but very often and freaks me out. I’m so scared I have something really wrong. I’m also getting pressure in the back of my head and pretty constant tension headaches. I keep trying to tell myself it’s from sleeping wrong or straining neck muscles. Has anyone else felt something like this?