Feeling like " poop"

Right now i feel like puking because, i went to far with hitting my best friend in a spot that should never get hit in. Right now i feel like killing myself pr doing something to myself. I hit my best friend, and now she is bleeding. Please can someone give me advice i need help. What do i do, what do i do. I started to laugh at first but then she said she was bleeding and I don't now what to do.???!!!!