Ok, I"ll chime in being that "guy" in your story.
The best thing you can do for him and you is to leave him. If you have children, then keep the lines open without any resentment and hatred. That will just lead to hard feelings and a hard life. Try to get a default divorce without any attorneys. And DO NOT leave him without taking your share, which will be at least 50%, the house and the children.
Some of us men need to get smacked between the eyes with a 2x4 to get our attention. As for me, I lost my house, family, church membership and even my freedom for a time. But I got back on the right track after many years and am back and active in the church. For heavens sake, I'm an ex'd member with a Stake calling! I call that progress and the Lord blessing me for turning my will over to him (well, I do have my moments, I am human).
I've also been through a whole lot of group therapies with the church and hardcore (and it's an understatement when I say hardcore) group therapy sessions. Separation is 90% necessary for both. He needs to be separated to see what he has lost and what he will lose permanently unless he straightens up and flies right. He also needs space to fix himself, if he wants to. If he doesn't, then you need to get that influence away from you and your children. You need the separation to be able to breathe, think, and see that you can survive without him and his obnoxious behavior. You need to do what you need to bring the Spirit of harmony back into your home since he will not share in that responsibility.
You have every right to be happy as long as you are doing the will of the Lord. Fast and pray about it. You'll make the right decision if you listen to the whisperings of the Lord.
I have dealt with many women (and some men) who are deeply depressed because they, early on, didn't want to see or face what was happening, and now, in middle age, being forced to face it because either DCFS, the law or both has forced them to.
BTW, my ex and I are still friends, we talk all the time, I work with her in her business, and I get to see the kids as much as it is possible for me. I believe it's because we have an understanding that regardless of what has happened, we still both have a responsibility to raise up the children. We so kept them out of our issues that it took a few years for them to realize that we are divorced.