Personally I think we have every right to be angry with our parents (or whoever raised us) when they have done us wrong and that wrong has had negative consequences on our lives well into adulthood. As children we were highly impressionable and our care takers had a large part in shaping our young minds and emotions so of course if they were abusive or neglectful, those actions are going to cast a very long shadow. It's not going to go away just because you are now an adult and responsible for your own well-being. That kind of thinking is just unreasonable.

Best thing I can say is now that you feel confident that "She doesn't get it", stop knocking your head against a brick wall. I too would love for my adoptive mother to admit her part in my past abuse but I know that she never will and that continuing to pursue that only does me harm.
Coming to terms with the past is so freakin hard. Hang in there.