Hang in there praying!
You did not ask for any of this. Nothing you did or didn't do had anything to do with it. I too sometimes think "If only I'd _____ she wouldn't be doing this" but it's not so. Your putting the kids first didn't make this happen. If you were the PERFECT wife (and no one is perfect) he would still be doing this. Listen to what he says himself, it's ALL about HIM. Believe me I don't get how they can be SO selfish either but they are. I feel the pain in your words and relate. I waited until I was almost 30 to marry because I wanted to be sure I found the right person. I made sure before I married that person agreed that divorce WASN'T an option. Then after 20 years when you think you're safe, I get a wife who is having an MLC and it all falls down.

I know it's hard but try and hang in and take it one day at a time!