Hi frazzlepop
What a nightmare for you and the rest of your family.
It might be worth speaking to your local police, they should have a domestic violence team or women’s aid .. Given the physical abuse you might be able to get a non molestation order and /or occupation order…sorry I’m not an expert but I know one of those is a legal route to getting him evicted and banned from coming near you, and your vulnersble disabled brother.
Even if your mum tries to stop you/the police etc just stay firm with your decision , it sounds as though you have nothing else to lose…you are fully within your rights to protect yourself and your disabled brother.
I’ve dreamed many times of just hiring a hotel room and chilling on my own to get away from my husband and get some peace …might just do that this Xmas,.sod the credit card already in debt what a an extra £150 or so, a.small.price for.some.peace and quiet
Hope things improve for you very soon