WTBH, I am so sorry you are struggling with this. I don't have young children so though I don't know exactly what you are going through, but I know how much I love my children and grandchildren and know I would have to keep fighting for their best interest.
My father is an A, my mother divorced him while I was very young. I have older siblings that lived through his anger and abuse of our mother as well as the older children. They still struggle with some things because of their memories of the he** he put our family through. I know without a doubt in my mind, my life was better having been protected from the fallout of his anger and behavior from my mother and I will always be thankful that she made the choices she did by putting her children first.
Some day your children will see him for what he really is and they will be thankful to you too.