Need advice

I’m in a situation where I unfortunately have to live in my parents house, so does my very abusive younger brother.

He’s over all a toxic person.

He threatens to hurt people, (and has on several occasions, mostly me. No there are no domestic abuse charges filed because our county/state is useless in domestic battery cases.), he lies to family friends often resulting in those friends dropping contact with us while staying in touch with him, spends most of his time telling me and my mother we’re both “useless b****es”, openly masturbates in public areas of the house (including in from of our 83 year old grandmother, he’s not naked; but it’s obvious what he’s doing.)

On top of that he generally takes advantage of my parents hospitality. Often verbally abusing both of them almost daily, especially our mother. He’s basically a man child.

My parents don’t seem to be able to do anything about him. )Like I said, our area is pretty useless as far as domestic resources.) While I pay rent and expenses, he doesn’t even have a job. He’s a freeloading leach.

I don’t think there’s anything anyone can do, but I’m at my limits. I can’t take the abuse anymore. I really don’t feel comfortable leaving my mother to be his victim.

Unfortunately I can’t financially move out. I’ve been trying, but it’s complicated.

Are there options for my family and I?