Your husband's behavior is not related to your behavior but to the fact that in his twisted mind you are the enemy. Whatever you will do or say won't stop his anger.
So stop blaming yourself for whatever craps he says or does. Don't argue with him, don't spew, detach ++++ for your own mental sake.
Did you read the thread on detaching? It's excellent, it not easy because it goes against our basic instincts, but at the end it removes your emotions to be connected to his behavior/reactions, it blocks their influence on us, it takes time but once you master it, you are "waterproof" from his actions and words.
Also it helps to reduce the tension between the spouses because you are not so prone to argue anymore. Deal with him as if he was only a neighbor, be nice and polite but nothing more. Request to be respected when he talks to you, do you know that silent treatment and constant spew are actually considered as a form of mental abuse. It takes a toll on your mental health after a while, you have a son, you need to be strong, you are the only sane parent right now.
He is under the illusion that once he will be divorced, life is going to be wonderful. So he resents you for being an obstacle, he is blaming you for his unhappiness, he knows that leaving his wife and his son is "wrong" so he persuaded himself that he reached that decision because you made his life a nightmare, he shifted the blame from him to you. From the villain he is now the victim.
Now when it's time to negotiate he might become very nice again, be careful, he has only his own interest in mind. So do and agree only to what you think are the best for yourself and your son.
You are not alone, keep posting, keep venting, it feels good to express frustrations and anger, also by sorting them out sometimes it helps to see the situation under another angle.
One day at a time, that's a very long journey, you are probably going through the worst right now, stay strong, he doesn't define you, your worth is not related to his opinion.
Big hug and good night,
Me 52+ WH 57+ Married 20 + Piecing since 2016 (ready to give up...)