Should i bring up something horrible my mom did?

I just found the site and decided to come out with something traumatic from my childhood. I'm not really all that effected by the thought of it anymore but it rocked me pretty hard at the time. My dad would work long hours at night and sleep in the mornings so he'd hardly be around, it was like that ever since I was a kid. I believe because of this my mom always liked partying and drinking and stuff. To make things clear, by partying i DO NOT mean doing coke or whatever the slang is; I mean going to clubs and such. Well when I was 17 she was really messed up, even for her. Her friend called me to come pick her up so I did. When we got home I laid her on the bed and took her shoes off like I usually did. I left and like an hour or two later I went to sleep myself. I woke up and it was like 3 or 4 am to find my mom naked on top of me. I thought I may have been dreaming or imagining it at first but that wasn't the case. She had my wrist's pinned and she was trying to angle herself so that I'd penetrate her. I wasn't aroused at all, I was quite horrified and shocked, but I was still had an erection. I believe it was what some call "Morning wood" but I can't say for sure. Well, it happened for about 2 hours or so and it was unprotected. I wanted to push her off during but it felt like I wasn't myself; almost like I was watching it happen to myself and wasn't able to stop it. That may sound crazy but it's how it felt. Well, after it had happened she had passed out on top of me, panting for a while and then drifting off to sleep. After about 30 minutes I wriggled myself from under her and left the room and took a long shower. She slept there for about half the day. When she woke up she called out to me. I didn't respond but I guess she knew I was still there. She wanted me to get her some clothes so I did. She got dressed then asked about last night and talked as if nothing had happened. To this day I still don't know if she remembers but I never brought it up. From that day I kinda distanced myself from her and she noticed and have brought it up several times as to what was wrong; I just brushing it off. I'm 20 now and have never told this story to anyone until now. What should I do?