I need advice...

You could ask her to teach you ways to handle the emotional abuse, and how to manage situations that may occur. Also skills to help deal with it in the present, and learn that his behaviour isn't your fault--- and all there is to know about emotional abuse that you should know of. Since it's a parental figure, she might suggest family therapy or groups for your dad to go to, although I'm guessing she'd consult with you first before actually mentioning any of them. If you don't want her to bring your mom to awareness, she won't, but make sure you take care of yourself and know that they're there for you!!