On Saturday, I went to my friend's 18th and I got super drunk, to the point where my friend sat me down with a group of boys and told them to look after me. After I'd sobered up a little, I sat in the kitchen with one of them and flirted with him. I went upstairs to the toilet but he was there on the landing and pulled me into a bedroom and started kissing me. He asked me if I was a virgin, to which I replied yes, and he was about to take off my clothes before someone walked in. Later, he pulled me into the bedroom again and this time he actually took my clothes off. When he undid my jeans I grabbed his hands to stop him and I stopped kissing him, but he broke free from my grasp and carried on, saying "no no no, it's okay, don't worry". I was tense and even though I was still drunk at this stage I was worried and slightly uncomfortable, yet not sober enough to tell him to stop so I just went along with what he wanted me to do. I was perfectly fine kissing him on a bed - I didn't have an issue with that and I didn't think it would go much further. I was attracted to him and he was funny and lovely and I thought it was ok. I also, for a few days, thought that it was a good thing because he was so attractive and punching well below his weight by getting off with me. However, these last few days I've been wondering if what happened was right. I didn't say yes but maybe he assumed I did because I was kissing him back? But on the other hand, I didn't say no either and let him do things to me and allowed him to tell me what to do to him.We also didn't actually have sex - we did other sexual things but technically no sex was involved. I just feel so guilty and dirty and gross, and to make matters worse my friend whose party it was is annoyed with me, claiming I disrespected her house and our friendship by doing things in her own home, which I respect, but I feel as if I can't talk to her about it. What should I do?