I'm sorry to hear things have gone this way. Sounds like your W was set on a goal...there may not have been much you could have done to turn things around....but it sure doesn't make this any less painful to know that now does it?
You keep concentrating on YOU...keep working on your other issues and remember YOU are going to be a much stronger person for all of this, you will learn from it, grow from it...and be a better mate for someone else in the future because of it.
Take care of yourself right now...and concentrate on being the best father to your kids that you can be (which I've no doubt you have been doing.)
Just because your M looks like it's ending, doesn't mean you have to leave us here...we're here for you as long as YOU need support!