Can't sleep heart beat is too strong?

It has been 3 months now and I can't go to sleep easily but since a week that I can only get 4 hours of sleep. My heart beats as if I ran from a bull. Why is that. I am always in front of the pc does that have anything to do with it? This did start with the start of the semester so maybe I'm nervous about school I do get nervous when speaking in class. Please help to calm my heart any treatments maybe acupuncture, hypnosis I dunno you tell me cuz I can't keep this up I have school