Oh honey!! So pi$$ed on your behalf right now
Please PLEASE call that DV hotline. It sounds like you have some safe places for you and your child to go for the moment. Maybe you could leave while he isn't there and have a few days to collect yourself and call the hotline from somewhere safe? Because people like him are natural disasters. They will blow around and blow over a million times. Until they don't and they can ruin your life. And, how long is it before your child will be in the line of fire?
As far as what to say to the people on the hotline - I am positive that they have heard stories worse than you could even dream of. They are there to help you and advocate for you, and you owe it to yourself and your child to be free of this fear.
Good luck! I will be keeping an eye on your posts and hoping for a safe end to this situation!