Can I go to sleep after hitting head?!

as long as your vision isn't blurry or doing wierd things, and you don't feel nauseated/ are throwing up, then i think it would be ok to go to sleep. I would suggest you have someone check on you periodically throughout the night to make sure you're still alive.
this is what they doctor told my parents when i had a concussion.

if you start to throw up or feel like you are going to throw up, have vision changes, cannot be fully awakened, go to the ER immediatly because you may have a serious head injury

2 concussions

wtf.