A "new" husband and wife in my opinion should live together when children are grown, on their own and experience new marriage. It could be that on your husbands side of things, a third party in the home of mature age is bugging him.
I would say that on your son's point of view he knows your husband hit you, has a bad temper, can't work out what you found attractive about a personality like that, cares for his Mother and seriously, as a child I would not like the guy either, who would? Isn't blood thicker than water, especially when any form of abuse is concerned?
Sounds to me that you realise what you married, hoping that the Bible will help change him but people don't change. Not quickly, and only if they want to not because someone else wants them to.
It also forgive me, sounds as if you are proud of your Son "and you should be" but put your husband down of non achievement in life. It has to be that way, or you wouldn't see that as the reason why they don't get along.
It sounds as if you are justifying "why" he is bad tempered, why he has anger issues, why he has put his hands on you, and that you believe it's from jealousy.
I would say it's been in his blood all his life and you either missed the signs or saw them, ignored them, thought they would go away and settled.
I wonder also to be honest, whether you like your son there as you feel safer.
Don't play favourites. That will always get up someone's goat especially when they are a new person into your life that you vowed to love for ever.
This could be what you are doing and why he is digressing to his true self.
Doesn't sound like a healthy marriage or safe one to me. Good luck.