I did something to this girl that i have realized is horribly mean and I feel awful about it.?

We were good friends and we went to a dance together (as friends). I after the dance there was a gathering at some hotels for partys. I hooked up with a girl after I drank more than I ever have (im still not a very experienced drinker. Anyway, I found out later that it was in her room that I did this disgusting act. I feel awful and now she's not talking to me. I feel so guilty and I just wish I could take back what i foolishly did. Anyone know how to get her to forgive me? Or at least help me move on from this embarrasement? It's the worst thing I've ever done in my life