AITA If I didn’t go to my dad’s wedding?

A little background information: My dad (39 m) and I (16 f) have always had a rough relationship. We fight constantly and it gets to the point where we have to be separated.
He had supervised visits with me as a kid once a week for an hour. He would show up 45 min late to each of them.

A couple years ago right when covid started we became a lot closer. We did everything together, he was my best friend. I even moved in with him full time. Our relationship finally got better and I felt like my dad actually cared about me.

He had been with my stepmom (38 f) at the time but they got a divorce after 12 years of marriage. KEEP THIS IN MIND.

Not even a week after my stepmom had moved out my dad had his new gf(27 f) move in. I was 14 when I met her and in the beginning she was fun and she was really sweet.

After a month of her staying there she was a total bitch. she found out i had lost my virginity and called me downstairs and had a “long talk”. she was calling me easy and degrading the crap out of me. It’s only gotten worse from there so I moved out back in October and haven’t talked to my dad because when he met her it was all about her not his kids.

My sister (11 f) and I are sick of being pushed to the back burner. We went from barley having our dad to not having him at all. I can count on one hand how many times my dad has hugged me or even asked how i’m doing. My dad never reaches out to me or my sister. He works with his gf and they even ride in the same car. They’re with each other every second of the day everyday and he wonders why we want time with him.

My dad called recently to go out to dinner and talk everything out. So I ended up agreeing because if I didn’t try with him i’d regret it. When he came to pick me up he just honked at me to come outside. The entire way to the restaurant he didn’t say a word to me… in the restaurant he didn’t say a word just stared at me the entire time. Finally we got in the truck and he started bad mouthing my mom. ( he’s done this since i was little) He was calling my mom a bitch and an asshole just saying some messed up stuff. I just stayed quiet until he dropped me off.

Idk what to do i’m just tired of trying so hard with someone and them not trying just as much. you can’t force a relationship with someone. I don’t wanna see him again.

would i be the ah if i didn’t go to his wedding?

***Also if you think you might be missing part of the story you are i’m just not comfortable with people knowing some of the story :)