Some musings on healthy selfishness; it is a tricky dynamic.
When we, ahem, finally assert ourselves...
and get the responses of further degradations, labels, finger pointing, all the way to full blown tantrums, or character assassinations...
I think it is a fundamental failure of the abusive ones to respect another person .
The retorts are not about us. We are still invisible and their anger comes because their needed supply of the phychological reflection is no longer a superior image. They still don't see the real us. They can only have their interpretation, anything else and their house of cards will easily collapse.
Being selfish enough to put your mental health ahead of the needs of an abusive person is a good thing, no matter the relationship. This is you acting for you, not using someone else (entangling your actions with their actions) for your mental health. The abusive ones can not see this; they can not see someone stand alone because that is such a foreign concept to them.
The name calling-"you are just like your mother" is a reflexive comment with no thought, no truth, and is a last gasp in their losing battle to cause as much damage through doubt as they can, "put you back in your place". Another attempt at a pathetic power play, or to preserve the status quo of, for example, you shielding your father. Tell him to pound sand next time.