the best you can hope for (other than her doing a 180) is 50/50 care of the children and move on. I know you don't want to hear it.
i refused to stay in an unhappy marriage, one where my wife would have hated me day and night, 'for the sake of the children'. I believed that it really would teach the children the wrong lessons...stay unhappy to make others happy. That does not work. I had (JW) teenagers in households like you discribe tell me that they just wished their parents had the guts to end it instead of making the fake happy family that made them miserable.
I can't say i have not at times wished i had stayed for the kids sake, but it is very rare. In the end, despite my wifes begging (even though she couldn't stand me) i said NO. I did reap the whirlwind of hate but I have had 14 years of rebuliding, during which time i have had a good happy life.
the real regret, is not having the balls and brains to fight for 50/50 custody at the start instead of letting myself get walked over big time.
Sometimes it just has to end, no blame. shit happens, people change. You both have the right to be happy and that probably means what you don't want. You are in a tough place and there are no easy answers.
sometimes only one gets happy again. my ex has remained bitter and vindictive, has alienated her kids. She didn't move on (even though she has remarried). I did. It was a choice. A tough one.
all the best
Oz