In my experience:
Being not-married is hard. Being married to someone who couldn't love me and who met my needs with aggression and abuse and made sure my children saw him "punishing" me was MUCH WORSE.
I was abusing my kids by having them see it. I might as well have sat them down with pornography and Quentin Tarantino movies and a bowl of popcorn and said "here, watch this."
I came to a place where I had to swim to the surface and take my babies with me. There was absolutely nothing more to it.
But yes, I had to be encouraged to do it, even then. My therapist had to say "he isn't going to change."
Life is full of joys that you and your children will never experience as long as you are married to him.