Possibly raped

So there was this one time when i was with my exboyfriend
And I told him I didn't want to have sex with him but then he did it anyway
I've always put it down to the fact that he didn't hear me
But recently I've been thinking that he probably did hear me and idk
It was a long time ago but I'm still fucked up and have been since that day
So much so that if i go to have sex now, I tense up before anything goes in and I end up hurting like fuck
I have really bad days and I still think that it was my fault.