Oh dear, your update was heartbreaking, please don't give up, ask MNHQ to move this to relationships. I think people are reacting this way because it's AIBU and we usually come here to enjoy a bunfight, and also the situation seems unreal, because he really has done a number on you, hasn't he?
I think you're in shock, and are trying to hold together the semblance of your marriage, because to admit it is all over is just too scary to contemplate right now, with kids and your home and your whole life as it is (was) on the line.
If I were you, I would leave him to his moping. He is not your concern. Instead, use the time and energy to contact someone like a counsellor, or Refuge/Freedom programme, to get your head straight FIRST, to work out how YOU feel and what YOU want.
He is not worth a single tear, the self-serving teen-bothering selfish careless cretin. HE'S done this to the family unit, to the kids, to you. He's put a grubby grope on a box of staplers over his entire family life. He deserves to lose the lot.
Jesus, I'M getting angry with him just writing this.