I had that a couple of times, it's either because you slept in a wrong position or your neck was really cold during the night. It's most likely a muscle that's stiff. I had it when I woke up, couldn't turn my head for a week and had to go to the doctor every day to get it massaged. In other words, you're going to be just fine Well, that could fit my story about spending 5 hours in the cold shaking my buthole off. I'm still going to visit a dokter though. Like, what if it's my central nerve system, and I get paralized. I doubt it would happen to you at an age of 17. It's just a muscle, don't worry about it.