I think her response is to be expected. At least I can relate, my X was the same.
I'm looking to you to identify what you believed enabled her reaction of getting a D. You are not a victim, you did contribute to the demise. All I have seen your write about is being withdrawn, perhaps I missed it. But laying out all the items she may believe will help you focus on things to become better and react in different ways to the situations that will face. By reacting differently than you always have she will notice. Actions speak louder than words.
I will use myself as the example...
My X would say that I was. Short tempered/Overreact, Condescending/Overbearing, Withdrawn, etc
I am addressing being... Short Tempered, by learning how to be patient. I read a book on how to implement techniques to give myself space so I don't overreact. I am trying to implement those. Condescending, by learning how to validate a person's feelings and emotions and trying to become a better listener... Etc
Me: 32 W: 29 T:8 M: 6 D4 S2 M - 8/2008 W is not happy - 1/2014 W wants D - 9/2014 W moved out - 11/2014 D filed - 1/23/2015 D'ed - 2/25/2015 Gave X the Letter - 11/10/2015