If you take a drunk jerk and clean him up and get him sober, you're still stuck with a jerk. Some people are just jerks, whether they're drinking or sober.
So, you took him back and now you regret it. That's okay. You can change your mind. Sounds to me like you have a very good reason to do just that. Don't listen to voice that says he needs you. He doesn't. He's not trying so hard. Yes, it is his fault that he behaves that way. Yes, he can help it. Love shouldn't hurt. You aren't abandoning him, you are saving yourself.
You deserve so much more than what this guy gives you. He sounds extremely selfish and hateful and he doesn't deserve you.
((((HUGS)))) Keep pedaling far, far away from him.