I can’t speak from experience on this one, but you need to make yourself happy first and foremost otherwise you’re children won’t be happy either. They will feel your pain. And if nothing more they have a terrible role model for their own behaviour which in staying with him you are condoning….
I hate to say it as I don’t have children so can’t know the pain this is causing you, but I really feel you need to make sure you’re happy and if you’re not you need to try to break free.
I hope you can find strength x