Reflecting on my first sexual relationship and feeling horrible

I started dating my ex right out if highschool. We both had zero sexual experience, my only sexual education was from porn.

Our relationship sexual relationship was very strange, we almost never talked about sex. Neither one of us discussed what we did and didnt like. I would usually start sex, both came, then continued on with what we were doing. I tried to make consent very clear, I would always stop if she said she wasnt in the mood, and told her it was totally fine for her to tell me to stop.

I also knew she liked rough sex, hair pulling and slapping she really enjoyed.

One day we are both drunk and i tell her i want to try anal, she says yes and we have anal sex for the first time. We do it again twice before she stops me and says it hurts, i of course stop and we never do it again. Later i would put my finger in her ass during sex, she never said no to this, and i assumed she liked it because of all the rough stuff she was into. But we had so little communication i am now starting to wonder if i crossed a line. I have talked with my girlfriends on how much they hate this (its usually in the context of partners just doing anal play by surprise)

Me and my ex would argue alot but never about sex. She certainly wasnt afraid to confront me about things and i was never violent or threatened her. I am just worried I crossed a line and it was never communicated properly. This all happened years ago and with future partners I have tried to be much more clear with boundaries.