You sir, have been disrespected more than anyone deserves. There are no good reasons for it, only excuses.
"Staying for the kids" is dumb.
So many people choose to be miserable because they think they are making some great sacrifice for the kids.
Then they wonder why their children can't seem to have healthy relationships when they get older because they have grown up in abusive, cold homes.
Better off with a strong, clear-headed single parent/ step parent.
I wish you luck.