Re: Help me, I think I'm about to make a "right decision" the "wrong way"
You find somewhere safe you can go with your daughter. There are shelters where you can find some safety and some counseling. Even if you are not in physical danger, your mind is not in a good place and you do need some counseling; you may not realize this until later. You take some things and go there when he isn't home. You contact him and let him know that you will not accept his abusive behavior any longer and that you would like him to leave. You explain to him very simply why so that he understands that you are asking this because of his cheating and abuse. And, don't give him a chance to blame-shift or gas-light you; be brief in your explanation because he'll dispute all the rest until you aren't sure of yourself any longer. Perhaps you can speak to him in a public place like a cafe, someplace where you have privacy, but where you are not isolated in case things go awry. You ask people who you do trust to be there when he takes what he needs and what is his; his friends or family, yours, police, whatever you think makes sense and won't make things worse. If he is unwilling or not inclined to go, then you go.
It is not wise to stay in a situation which involves both abuse and infidelity. If your WH respects you so little and you never follow through on your boundaries and never let him know that there are consequences for crossing those lines of trust and respect and safety, then he will keep doing more and doing worse and when it escalates, you don't know where it will stop. You must be strong enough to stop enabling his behavior, strong enough to keep yourself and your daughter safe, and strong enough to show him that he is hurting you. He will never change if he cannot, himself, see that he is wrong. Until he recognizes that he has hurt you and crossed a line, he will never ever see that the line exists and that his behavior is hurtful and unacceptable and he will never even have a chance at change. And you should not have to feel unsafe in your own life. You do not deserve to be the punching bag for his own insecurities, issues, or frustrated notions of privilege.
Just my opinion. If you feel like your life is in danger, though, leave right now. He can take care of himself and, as you mentioned, he has all the other OWs there, too. No matter how you handle this or how kind you are to him, he will likely turn to them for support anyway. But, you are risking more in choosing inaction out of fear of this than you are in being honest and standing up for yourself and your daughter.