Its definitely not on you, all the nasty things he says is to make you back down which allows him to do as he wishes. Honesty with his family is best I’ve been in your situation too and once I had told his parents the truth they managed to fit the puzzle pieces together and see it for themselves, unfortunately sounds like shes lashing out as she doesn’t want to believe it.
Im so sorry for what you are going through. Its hard to know when enough is enough. You need to look after yourself first.
I am out of this relationship now but I was in such a bad place then I was relieved to be away from it all. Although I find myself in a very simular situation now.
I understand exactly how you are feeling and I hope things improve for you. X