Sounds as if she was a bit rough with your penis! Girls don't always know how to handle our equipment and we need to do a little teaching. So, next time if you're sensing she's a bit rough...ask her to loosen up a bit. And I'd use some lubrication, that would probably prevent this from happening again. About your condition now....should be no problem and they'll heal on their own. I'd be careful though and not do to much masturbation for a few days....give your buddy some time to recover!