Would you be upset too, or am I over reacting (long question)?

My mom has really been mentally and emotionally abusive. I had to set bounderies with her and she couldn't stop undermining me as a parent, and trying to control my life. She has this way of 'getting in my head' and telling me how to think and feel and act. She never did hear my bounderies, so I had to push her away harder and harder. Finally I had to get rude, and she FINALLY heard that, but wouldnt' stop. So I had to move away with my kids. Things are a little better now. So last night I asked her if she feels 'we' are better now. She said that this all started with my dad (who is evil). I told her to stop trashing my dad, but she couldn't. She said 'someday, I will see that she speaks the truth'. I told her to stop trying to have one up on me with 'someday you'll understand'. She tried and tried to convince me that my dad is bad and that he is 'a master manipulator' and that is the truth. I became upset which made her realize that "I" was not ready for this conversation.