Toxic Relationship vs Children

Anyone had gone through a toxic relationship? How do you deal with it? I always make my child my priority and truly I'm not happy with my relationship. He's abusive and always cheats. I kept quiet because of my child and whenever I'm pregnant he will go with another young girls... more shockingly is a secondary school girls who's willingly go with him. There's this girl who's only 14... asked me to let go of my husband because she wants with him. I was 7 months pregnant. I don't know what to do... and now I'm in my second pregnant... He's abusive as always... and my stomach hurts right now