Flashback causing questions - clarity needed

I don't know what to do or where to start.

I don't know if this is rearing it's head because lock down means more time to think or because it's coming up to the anniversary.

About 3 years ago I had a FWB relationhip with who I thought was a good guy. The last time we met was different.

I wasn't 100% in the mood. I wanted to hang out rather than anything else but that changed. We were making out and it quickly built to sex (anal because for some reason I didn't want vaginal). I was into it and enjoying it, but a couple of times he tried putting it in my vagina and every time I said no he'd take it back out again.

He did it again a bit more forceful but because I was in the zone and he was doing other stuff, I started making a noise in my throat "hmm hmm" sort of thing indicating no. At least I thought I was.

Long story short he didn't pull out and he released himself into me. When he was done, he dressed himself, said sorry and walked out.

It left me feeling dirty. I questioned this for a while after and have been doing it alot again recently: asking myself if it was rape (although not in the strictest sense), did I deserve it, did I do enough to try and stop it?

I can't talk to anyone and definitely need clarity on it