I want my husband to leave.

TBagpuss

I agree that step one is for your brother to serve notice requiring your husband to leave, but be prepared for him to dispute it.
If he claims that you are tenants then you can apply for an occupation order (injunction) if he is abusive towards you - this can be abuse which falls short of physical violence) - an occupation order does not change the rights you have longer term but it can exclude him from the property for between 6 and 12 months, which hopefully would be long enough for you to sort out a divorce and for him to sort out other, long term housing for himself. 
It would then be sensible for your brother to put something in place more formally for you so you have a bit more security, and for him to make sure that his will is up to date and clear about you being able to remain or giving a firm timescale for you to make alternative plans!