Sorry you're in pain MissInvisible. Did you injure your neck? If you didn't injure it and woke up that way, I don't think you need to worry about a torn muscle. It definitely hurts though doesn't it. You can apply an ice pack for 10 mins but make sure you cover it with a light cloth. Take some ibuprophen if it doesn't bother your stomach...always with food. Hope you feel better soon.