I’m sorry you’re on your own with this. Really I am too. I’m married but my spouse is not his father (he died when he was a child). My husband is very supportive of me, but he easily puts him out of his mind and doesn’t feel all these things like I do.
Your situation sounds familiar. They get nasty when they don’t get what they want- my son has done that many times. I had to stop giving him money years ago.
Good for for seeing that you have to start setting some boundaries with him! It’s the only way to help yourself.