Jpeg...I read through Georgia Bulldog's advice to you as if it were written for me. I plan to take the same approach, starting immediately. I will write one last letter explaining why I'm discontinuing all contact, and putting everything on him.
After that...I'm fine with nothing. His affair with OW has caused him to treat me with the worst kind of disrespect, and I am ready to stop looking for good in all the crap. It stinks, period! I refuse to speak with him, already, confining communication to writing only. I can go even further with that. Now we have text wars, and I'm sick of that, so choosing an intermediary is my next step.
Like you, I want to be true to my faith, beliefs, and vows. It's clear to everyone that I'm in a bad situation with a selfish manipulative H. I see much of the same in yours! I never thought of affairs being abusive...but they hurt far worse then the ugliest comment he's directed at me. Worse, he's hurting the kids, too!
I'm struggling with many of the same things you are. I was (sadly) happier when the kids rallied around me in defense of their dad's evil ways. As they began to miss him, they started wanting to see him/talk to him. I'm a bit ashamed to admit I was hurt by that. I KNOW no good parent wishes alienation from the other parent on their children. I KNOW it is in my kids best interests to have a great relationship with their Dad. Still, my own selfish heart sent out a protest. I wish I were a better person. I kept it from the kids, of course, but the impulse to keep them close was there.
I'm doing LRT, pitch black. It will take a while, I'm certain. His affair with the pretty young thing who has nothing better to do than fawn all over "her man" is still really new, as well as weekends only. Heck! Even I could be extraordinarily charming if I only had to be perfect for 2 days. LOL
I've got so much healing to do. H really hurt me. I'm going to be completely selfish and not worry about him while I repair the damage he did to me, and make sure I'm never open to that kind of hurt again. I want to keep most parts of me and build them up. Other parts, that led to breakdown of M, I will resolve one way or another. I will come out of this whole, happy, and content...with or without H (even though I can't imagine that yet!)