Every night when i go to sleep i wake up withmy heart beating really fast and i can even hear it in my head! is it something serious?

Probably not, but...: Whatever this is, it's obviously bothersome to you. The most likely cause is something called supraventricular tachycardia which means a fast rhythm from the top chamber. Of that, there are 3 common types. A cardiac electrophysiologist can help you sort that out with an "event monitor." if an ep isn't available, a general cardiologist can help.