I had a fist fight with my friend for her car keys because she was drunk- am i wrong??

I had to fight my friend for her keys. She was smashed!! I did'nt intend on fighting her- but she was determined to drive home. She woke up the next morning with a black eye and lots of scs and bruises. I did not intend on hurting her- but she was swinging like a wildcat and i had to slap her around a bit and tackle her to get her to calm down and not get in her car. I feel really bad - but i was wondering if I should feel bad at all and hope that she learns from this.