I'm a parent myself. I've also suffered considerably with mental health in the past. Anxiety and depression. From your Mothers' perspective I can imagine that she feels a lot of guilt about how she treats you. Even though she can't help some of it, she will feel it. The possible NPD issue could also prevent her from revealing her guilt and/or shame. There is no question that she loves you. I can tell you for sure that a parent cannot stop loving a child!
But..
You still need to find your own path with this. Being independent is only scary at the start, but take it step by step. You can't wait for her to get help before you get help yourself.