It's a tough situation you are in.

Yes, start your own bank account and putting money in it. Get yourself a PO Box at the post office for just you.
I would be making an appointment with a CL person and explain your situation and what you want and then see the services, entitlements you can get.

Perhaps even talk to the Salvo's or St Vinnies and see what advice they offer. Sadly they would see this sort of thing alot I imagine. They probably have advisors that would point you in the right direction.
It may be wise to start copying things like house deeds, his bank statements, share portfolio's, investments and anything financial that he may be able to hide if and when you decide to leave.