Need to come out and break up with my bf

I’m 16(f) and I’ve been out as bisexual since 8th grade. I’m pretty open about it and my bf knows and has been cool with it for the most part. We’ve been together since October of last year and since then, I’ve been on a bit of a journey with my sexuality and gender identity and I now know that I’m very much a lesbian. I know it’s not fair to my bf or to me to stay in this relationship, but idk how honest to be about why I’m breaking up with him. I don’t have a problem being open about my sexuality, but recently he’s said some things about the LGBTQ+ community that make me uncomfortable and when his friend came out as nonbinary wasn’t really supportive of them. My bf also was super unsupportive of me wanting to wear a suit to my cousin’s wedding and said that people would think we were a gay couple. (I wore one anyway and he didn’t come.)

Anyway, if anyone has advice on how to breakup with my boyfriend I’d appreciate it. (And I have to come out because I like this one girl so much and we’ve been talking a lot more and there’s a pride event she invited me to and I want to post about it openly.)