got fingered while wasted

Jen
Last night I went to my first rave.
Let me start by saying that I am 20 years old haven't been the most adventurous. I struggled with an eating disorder from 14-16, and then was forced to attend an incredibly strict boarding school from
17-19. Because of this, I don't have much background with sex/masturbation/etc.
At the school  if you did anything sexual with another student, you could get suspended/put out to work/etc.
I've been at college for almost a full year now and last night my friend convinced me to go to a rave with her for her birthday. As this isn't really my type of thing, I said sure and made sure to get wasted beforehand in hopes of not ruining her time.
While there and very intoxicated, a guy asked if I wanted to stand in front of him
Because he was very tall and I couldn't see the bands. I did so and with a few minutes I felt his hands on my waist. 
I was nervous, but also kind of like "whatever fuck it I feel nothing."  Then his hands began to move up and down my body, and he began grabbing my ass. Again I am an absolute mess and have no idea how to deal with these types of situations. I don't go out of often mostly because I have an incredibly hard time saying "no." I just can't. I'm incredibly easily manipulated and because of it I tend to stay home where I can't get into trouble. 
He began to grind on my and one of his hands grabbed my tit and I felt so guilty because I've never had sex before and it felt so good to be touched like that by someone else.
Then his hands went down my shorts and he began shoving his fingers up in my vagina. This was painful as fuck and I had no idea why to do. I put my coat in front of his hands because we were in a very dark, yet public rave and I had no idea what to do with this situation.
After that it gets kind of blurry and
My friend said she looked over and I was like asleep (?)  like leaning on him but my eyes were closed and I wasn't really responding to anything. I don't remember much after that. 
I kind of came out of it at once. I got really shaky because I didn't really know where I was at first? He moved on to another girl and I went to the bathroom and cried.
I woke up feeling really shaken by the whole thing and canceled on the date I had (with someone else) today because I was afraid what might happen (we were gonna Netflix and chill). 
I think part of this was because I'm 20
And felt pathetic for not having had sex yet. I dunno. I'm just mad at myself because I feel like I should have stopped him but I didn't know how ??? I don't know where to go from here I just feel sad and gross