Hey man,
Short summary is: the girl really liked YOU and not the your game, cause it seems like you weren't playing a very good game. Forgive me for being harsh here - but she takes you to the room to at least make out and everything she wanted was to be gamed a little smoother, not just like : "You are horny, I am horny - lets fuck" - type of deal.
What you encountered is in fact a well documented phenomenon and is called a "Last minute Resistance" or "LMR". Mystery has done a good job on explaining origins of it - try googling.
So I guess now you are dealing with the situation where the girl thinks that you are a just another jerk and there is nothing special about you. There is really no 100% way to turn a missed opportunity back into an opportunity, but I would try to communicate something along these lines:
Hey, just wanted to let you know that I am sorry for acting like a jerk yesterday. I guess I was drunk and misinterpreted the signals you were sending. I thought you brought me to that room to hook up and were just teasing me - so I didn't want to disappoint you by being "hey, let me introduce you to my mom first"-type of guy

) Anyways, I hope you understand my point and we are cool. Say hi to your friends - they have done a pretty good job on not letting me to explain myself to you that night

)
not sure how it is better for you to communicate this - maybe via facebook or something... You should convey that it was sort of drunken misunderstanding on BOTH SIDES - don't just plead guilty! If she responds positively - shoot shit with her for a little bit and then offer to hang out in a company of common friends and then take it from there.
Good luck and next time try to pay more attention to what girl is saying
Dunkan.