I've been in this position from time to time. Once it got so bad that someone cloned my blog to try and get me arrested. So that was fun.
Point is, abusive toxic people do not really understand that they are abusive and toxic. If they know that they're hurting you they'll have some convoluted rationale that in their mind justifies it. They know how to hurt you and have no compunctions about it.
Buuuut if writing helps, you should write. I know you care about these people because a.) they're your family and b.) if you didn't their words wouldn't hurt. Additionally, *good* art is messy and offensive. The toxic people in your life will try to control the narrative but ... if it's so offensive to them let them compete.