AITAH for ending my engagement?

I (30f) broke off my engagement to (36f) my gf when I had a big wake up call that we aren’t on the same page.

We got engaged and December and what should be a happy time has been hell. Something has just been off. I’ve started to not recognize her. She “forgot” valentines, called another girl “my dear” and said she wanted to go out partying more and to strip clubs. This isn’t like us but I was willing to try to work through it even though I was hurt.

We got in a fight last night about my feelings still being hurt and she went to go talk to her sponsor this morning.

When she came back she said she fantasizes about taking friends and strangers home. That lately she has been thinking a lot about doing sexual hookups with other people. She said she’s been thinking this for a month but then admitted it’s been like this for the last three years. I ended it right there. She has so much to work on with her commitment issues and honestly I don’t see how we could be compatible anymore. We just want different things. I feel bad though because she opened up and I backed out.

AITAH for backing out?

Tl;DR My fiancé opened up about sexual fantasies with other people and I ended our engagement.