AITAH for avoiding my daughter?

My (41M) ex (41F) came out as a. Lesbian at the start of last year and we split. To say I was gutted is an understatement.

I have a daughter (17) from a previous relationship. Even though my ex isn't her mother, she classes her as her own and we've raised her together since she was 2 when my ex wife died. So she's not her biological mother but she is her mum if that makes sense.

They've been like proper mother and daughter for years, but the only down point in their relationship was when my daughter announced she was gay at 15. I was hugely supportive and didn't care but my ex really wasn't supportive at all at the time. It devastated my daughter hugely and we had lots family arguments. So imagine the surprise when my ex announced she was a lesbian after all that. So even though I hate my ex, I have to keep it civil and co-parent with her. She's actually delusional though and thinks we're "best mates".

We technically share custody of her and she basically spends her time between the 2 of us - we didn't have an official arrangement, we tried to do it all amicably. But truth be told, she prefers spending time with my ex. She's basically become her bestie. My ex is always sharing little Instagram and Tiktok stories about being a "late blooming lesbian" and my daughter loves it. Always liking it and Is the first to comment. In contrast, my kid hates spending time with me now. She's fucking glued to her phone the whole time, then sharing stupid tiktoks with me and then can't wait to get out the door. Any shared interests we had, is now gone. If it's not LGBT stuff, she doesn't want to know. She's always lecturing me on some fucking left wing shit.

Last weekend, my daughter was supposed to spend time with me and we were supposed to go to the rugby together as our team was playing away - we always went together and we were season ticket holders and she loved away days as much as I did. It was the last thing I thought we enjoyed together. But she said she didn't want to go at the last minute because of some bullshit important event with her friends I didn't previously know about. I was gutted but tried to pretend I was understanding. So imagine my surprise when I saw her Tiktok spending time with my ex instead and not with her friends like I thought. And not only that, I saw my exes latest social media post from the same day but then talking about being free and happy and my daughter commenting saying how happy she is for her, that she deserves to be happy at last and how proud she is of her! Like hello, do you remember how unhappy she made you when she came out?

So I was avoiding my daughter's texts/calls this week and fobbing her off like she did me. But she then messages me out the blue saying oh hi dad, do you want to hang out this weekend and go to a home match together? I was like no, go and hang out with your mum who you prefer spending time with and are so proud of. She tried to act all shocked and upset so I just muted her for a bit. My ex then tried to get in touch about it saying how upset our kid is so I told her to fuck off and all and spend some time together. My daughter even got in touch with my mum who tried to talk to me about it. Now my mum usually is the only person who's 100% on my side but even she was buying into her sob story and how I should at least hear her out. I told her to shut up about it too.

I genuinely don't know now. I'm confused (and possibly am a bit drunk still, ha) hence asking complete strangers for their input. AITAH?