Hopefully I don't offend anyone, but I used to be very similar to this man...I wish I could tell you that you can save him but you can't, he has to save himself. From what I'm reading he isn't even trying to do that, he doesn't realize he's a monster yet. There are programs and people to help you get out as other users have stated.

I'm not qualified to give you any diagnosis on his condition, but if he's the monster I was it has absolutely NOTHING to do with you, the kids, or even the cat. There is a chance he will get better, but you shouldn't stay in the situation until then. My wife stuck with me through all of it, it took me years to heal and I'm still not all the way there. We are 18 years in and it's finally safe enough for her to move out and rethink the marriage. It isnt worth it for you to be damaged by this in my opinion. Leave before you're truly trapped, further damaged, and regret the one life you have to live. Maybe being alone will force him to face what he truly is...