My ex wants me back: HELP

Sorry in advance for the long post!

So I was with my ex for about three and a half years until I broke it off in August. I broke up with him for various reasons, but here’s the short version: I had caught him talking to women multiple times, he met up with a woman one time and kissed her, he got physical with me 3 different times while he was drunk, one time where I’m pretty positive he fractured a rib, he would never communicate with me, and he kept his emotions in until it got so bad he would blow up on me.

Well since I broke up with him in August, apparently he’s been going to therapy and is really changing. He communicates a lot more now and has stopped drinking entirely. He really seems like he is making good change. The problem is that he is making these changes in the hope that I will get back with him.

Part of me is really happy he’s changing. He needed to do it for himself and his son. The other part of me is absolutely pissed off because I asked him to make these changes for the over 3 years we were together and I wasn’t enough until I left.

I’m not really sure what I’m asking for here, but if someone could just give me some advice, i would appreciate it (even if that advice is to say “fuck him” then that’s okay too).