Hello, OP. I started reading yesterday but this is my first chance to post.
Not only am I sending you a hug, I'm sending you a virtual box of them, so you can have a hug whenever you need.
The end of a marriage is a horrible shock, especially if you don't know it's coming.
He has given me virtually a books-worth of all the things that are wrong with me and our marriage
To quote your daughter, 'the prick'. He's rewriting history to justify his behaviour.
Advice from someone who has been through it...
Cut the OW out of your mind. Not your responsibility. We don't care about her, who she is, what she looks like, what her children are like. We know she opened her legs for him and that was enough. We don't have to think of her any further.
Get angry. What he's done to you is outrageous and his behaviour is cruel. You don't deserve this. You are worth more. He's out of your life now.
'Coming back' is something so many faithless husbands try, usually for financial reasons, though they won't put it like that to their wives. Some come home to get their housework done. Don't fall for it.
Now you have cried and begged, stop. Ice cold. Grey rock him. Get your legal and financial stuff in order, sell the lovely home. Start planning your life without him. It will be fantastic. He will be jealous as hell but you won't care. Forward!
This is not your fault, so don't blame yourself one bit. No matter what he says. Don't listen and don't care. You did your best. He is unfaithful. The fault lies with him.
Cry when you need to and give yourself a minimum of two years to recover.
Best wishes.