I was at this party waking up next morning with my knickers and legging down around my ankles

I had been at my parents anniversary party in their house alot of people were there I didn't know

It was my parents anniversary party they had been married for 25 years now it wasn't a special anniversary party but they had one anyway.
There was lots of people there that I didn't know. I had no idea who they were
I had been talking to different people having different drinks and cocktails.
My parents were enjoying themselves as I was talking to them
I was out in the garden having a cigarette and I was just standing there when this guy that I never knew started talking to me he's alot older than me he must have been in his 50's
While I am 21.
After that I just couldn't seem to get rid of him everywhere I went he was there it was like he was following me..
I was still drinking after a while later I was rather drunk probably drank too much as I was staggering about the place
I went upstairs and basically fell on top of my bed I must have passed out straight away..
Next morning when I woke up my top was up around my chest my bra was pulled down away from my tits
And my knickers and legging were down around my ankles I'm lying there trying to figure out what happened as I was fixing my clothes
My head was thumping and my stomach was churning I had a hangover from hell.
And I was thinking that I must have been raped while I was passed out drunk
It was horrible knowing that someone could have done that to me while I was passed out drunk on my own bed in my parents house
I was really scared thinking about it.
I didn't feel anything I must have been that drunk.. It really scares me to think that one off my parents guests at their anniversary party could have raped me while I was passed out