The Children:
Your daughter tells Daddy that she loves him, but he won’t reciprocate. Cruelty personified. That will have damaged her self-esteem. You’ve allowed it. I assume he is also unaffectionate with your son. They both would have noticed his lack of affection for you.
Your children witnessed your quasi-polygamous set up where Daddy seemed to have two wives. This would have confused them. Auntie & Daddy sat together on the sofa, went out to do hobbies together, made household decisions, and ignored Mummy. Auntie walked around in her underwear in front of Daddy. There’s no telling what else they witnessed.
Your daughter likely saw the violence in October. She ran out to plead for the fighting to stop. It is possible that your son also witnessed it, but you weren’t sure. He had not mentioned it. H thought it appropriate to aggressively manhandle you, and he didn’t care if the children or his mother saw or heard.
You cannot gloss over or rationalize away any of the above. All of it has been damaging to your children, and you and H have set a terribly unhealthy model for their future relationships.
The Adults:
In 13 years, H has never told you that he loves you. He never demonstrates any affection for you outside the bedroom.
So OW coerced him every time they had sex for 7 years? 
He has conned you again. You are repeating your ostrich pattern. He has you feeling superior by demonizing OW and by claiming she was jealous of you and wanted your life. Diddums had to submit to her for all those years.
Her intentions don’t matter. She is a distraction. You are minimizing his long-term adultery and his utter contempt and subjugation of you.
He defiled your family and home with her. They shared intimacy wherever they went. It sounds like THEY have had the primary relationship. You were secondary and they made you watch while they stomped on your dignity. You say they made joint decisions about your life and ignored you. He wanted it that way. The idea that he was coerced is ludicrous.
You allowed their relationship to flourish in front of you. The signs were flashing, but you kept your blinders on. You pulled them off briefly in 2014 and again a few weeks ago, but they’re firmly on again.
You are again being manipulated. Where are your self-respect and anger? After all his lies and deceit, it is astonishing that you believe him and want to be with him. He is the true monster here. Your poor children.
You would greatly benefit from individual counseling to strengthen your self-esteem and boundaries, and to learn why you are willing to settle for so little.