I'm tired of trying-he isn't going to change.

I (26F) have been in therapy for ten years now working through various traumas from my life. A lot of this trauma centers around my father whom I love, but has no clue how to be a dad. I was raised by his mother while he spent time getting his life together, which was honestly for the best. He has had a violent and verbally abusive past will me, his mom, and a couple of my cousins, one event resulting in him actually committing suicide. Thankfully the ER was able to bring him back and since then he has claimed to have "changed". Well among other events, about 3 years ago he didn't attend my graduation. Not that he wasn't invited, he just didn't care to keep up with the date and time. We'll he recently began to text me very vulgar statements about things that he heard from gossip, like him thinking I'd bring my dog's to my grandma's house when she didn't want me to. I didn't bring them of course. I know he gets to drinking and that makes it worse, but what kind of dad talks to his daughter the way he does? Then he texts me saying he's sorry but it's my fault because he's mad I let him miss that graduation 3 years ago. IT HAS BEEN 3 YEARS. Since then he's been to my master's graduation and my wedding! And I even let him walk me down the isle to avoid another blow up in our family from him! Noone can change what happened 3 years ago, I already told him I'm sorry and that I did want him there, and with my mom dying this year I thought he'd want to get closer and not further. I just can't keep trying. It's exhausting and I have a panic attack every time I get a text from him, scared about what he will say or threaten next.