But it was never amusing. You thought it so as a way to protect yourself. It is harassment. In a marriage, it is called abuse. You have been so close to it for so long, you don't realize how toxic it is. You seem think it is just part of the atmosphere, but it is not. You seem to accept it as just part of life. You should not accept this.
When I read this how your X behaved I was so appalled I couldn't respond. I think the legal way SPM suggests to respond is also absolutely correct.
Please take these steps. The written component is important because it will document the abuse.
I guarantee that once you start setting firm clear boundaries you will start to heal and grow MUCH MUCH stronger.
You and your girls deserve so much better. And your girls deserve a role model of a mother who won't accept unacceptable behavior from anyone.
SG
Survival Goddess "The most common way people give up their power is by thinking they don't have any." -Alice Walker