Separating from toxic brother is harder than I thought

My brother has always been different, he's been physically abusive towards me and my mother since he was 9. He is extremely controlling from trying to dictate my wardrobe, comments on my body like how my bra is to small for my boobs (which is weird af), to attemptingto scare of any man I date. He actually said not long ago he's angry at my husband for taking me away(wtf?).

He's always been overly obsessed with sex, ex: he doesn't care who he gets off in front of. And has actually gotten in trouble for being to touchy with people at school, sometimes it would even end in a physical altercation with other kids.

He's 18 now and my entire family acknowledges something is really off with him and has been since he was a child. But nobody has ever helped him to get therapy or anything for his issues. I begged my parents to get him help while he was a kid but now that he's 18 it's to late.

I'm 24 and 8 months pregnant with my son. Me and my husband have already decided we don't want our child near him and I'm cutting ties with my brother until he gets actual help with his anger issues and other problems. My family is completely against it saying he's just a kid and knows no better or that he'll change. My favorite is when they say he loves me more than anyone (It didn't feel like love when I had to barricade myself in my room to avoid him hitting me).

I said I would go to family therapy with them to work out what's wrong with him but nobody wants to do it.

I don't want to lose my whole family but I feel my brother is dangerous and shouldn't be around kids because he's such a negative example. I don't think my extended family knows completely about all his issues as my parents hid it, and I don't know if it'd help to tell them or if they'd care. I just don't know what to do