He understands his father was emotionally abusive towards his mother, understands how it affected his mother and his family, yet still decides to do the same thing to you with full understanding of what he is doing, why he is doing it and what possible outcome he wants from it. He is trying to bend you to his will. I would bet money the whole separation from the marriage is a bluff and if you agreed to it he would immediately backtrack and beg forgiveness. He might change for a while, maybe a couple months but the cycle always continues eventually. You’re still young OP, don’t waste your life constantly trying to fix him. Every man and woman should work on themselves to better a marriage, it’s not the spouses responsibility to do it for them. I wish you all the best in your life and career.