This happens to me about once every two months. If you look up nocturnal anxiety attacks it explains it. They always happen to me an hour after I have gone to sleep too. It was a panic attack trust me on this. I have noticed a lot of the time they happen when I'm over tired. If I were you I would go to school because it will be a distraction to get your mind off the anxiety and not make it worse. I find if I just sit around athe symptoms get worse. If I'm busy I feel better, that's just me though. I don't think your sick I think it is anxiety for sure.