Aw Paulos.........I'm so sorry you are going through this.
there's NO JUSTIFICATION for how she's treated me
You are sooooo very right! Nobody should be called those names by anyone, let alone your mother. I have always found that when I have been angry at my kids (and I have been), that I had to look into myself and examine what the anger was about..........most times, it had nothing to do with them or what they did.....it was the situation I am living in (with an AH). I feel helpless and hopeless sometimes and have come to recognize that I take it out on those I love the most. I have stopped doing that. This is not to excuse the behaviour, it helps to explain it however. It's her disease, not you and again, you are right, there is no justification.
Please do what you need to take care of yourself. What can you do that can help to make it a better day? Try not to listen to those words because as you probably know, it's not about you.