I want to get revenge on this person?

I've been through a lot. Abusive dad, crappy relationships, but I do not hold it against them. But this one girl.. I wish she'd die. I've never thought this about ANY1, not even the pig that raped me. On the night of graduation me and my best friend watched our graduation from across the street to avoid trouble ( I got high honor rolled but I was afraid to go because I had been threatened) I lived right next to the school so I thought it'd be "safe", boy was I wrong. After about 10 mins I saw them. I was honeslty to afraid to move so I too my friend to dial 911 becuase if I did, they'd really kill me. I regret not callig 911 myself. There were about 12 of them. 2 of them were actually FRIENDS of mine! They did nothing to help me. They squished a bug on me. I felt bad for the bug.. I was ok untill they poured a bottle of piss, dirt, and rocks on my head. Then she started punching me. I did not know what to do (never been in a fight) so I just grabbed her hair. After a guy (who hated me but decided to help) pulled her off. They walk off. My friend hadn't been touch. I was left with a broken nose, open gash on my head and bruises all over. One of HER friends even recorded the fight.. And guess what?? The cops finally came on a golf cart and they didn't even care! She acted like I had done something wrong!! I couldn't believe it. That night scarred me. I wish the "leader M." (not going to say her name..) would die. Does this make me a bad person..? Is it normal...?? I want to beat her up but I dnt want to stoop down to that level.. I dont want her to get away with it though because she has done this to multiple people! What should I do..? Am I a bad person for wishing that she'd get hit by a car and die? I have been having horrible nigtmares about that night.. Should I tell my boyfriend.? What if he doesn't understand? He thinks the world is amazing. He has never had a bad experience with family, friends, or strangers.. I honestly feel a little better getting my feelings ou there:( sorry for any typos and please no mean or harsh comments..