don’t know what to do

I’m 16 and this happened only a couple of months ago, I was drunk and I was lying on my boyfriend who was drunk aswell my best friends boyfriend wasn’t drunk and he was sitting next to my boyfriend, he started to rub my privates and tried to finger me. I was comPletely out of it so I didn’t know what to think of it at the time and he isn’t my best friends boyfriend now but he is still in our group. I stopped going out because I didn’t want to even see or look at him but I’m going out tonight and he’s going to be there, anyone got any tips for me to cope with this as none of my friends get how I am feeling atm.