Jenna,
Yes, you have OCD. I've had it for 28 years and the light switch thing is the first thing I can remember it surfacing on. Please, please tell your parents. If I had done so, even though back then they probably didn't know what OCD was, mine wouldn't be as bad as it is. There is help available. You are NOT crazy, although it feels that way sometimes. Get help so you don't get worse.