Narcissists and borderlines may seem like monsters, but they’re not monsters. They’re human. Like anyone with a personality disorder, they have a disorder, not a choice in being who they are. Where they do have a choice though, is in whether or not they get help and try to manage their problem. That’s where the line should be drawn.
When you stay with one beyond the initial phase of understanding they are toxic, you become a willing part of that dynamic. So since you’re there, and you don’t want to further wreck the kids’ lives, the answer is obviously to get help. Both of you need to see counselors who are specialists in personality disorders and codependents.
Be advised that so long as you don’t get help, you are teaching the children that what is going on between you is good or normal. So do get help. Do that for the kids.
Just try to get counselors who are men’s rights aware. Otherwise, you are just signing up for being brainwashed about how everything you do is wrong and everything she does is right. Follow this link: Shrink4Men