sorry, i think she is just being an addict. her behavior is kind of typical. try not to continue to beat yourself up. it is what it is. unless you are able to except that she is what she is and has done what she had done, it will take you much longer to be able to move on.
i know how you feel though. my ah of 23 yrs have say and done cruel things to me too. when my brother passed away, ,my ah looked at me a laughed. now that was painful but i had to look at it for what it was. i was rushed into emergency surgery, on my death bed, they thought and my dear ah chose to stay home and do drugs. he didn't even think to ask the paramedics what hospital they were taking me to. my kids had to find me in order to sign papers i needed that would allow them to try to save me.
i said all that to say, when in active mode, an addict is thinking only about getting high. its nothing personal for them, its just the way it is. maybe its time for you to find something you can focus on besides her and her behavior. reliving the past, will only cause you to feel worse. who knows the mind of an addict? i'm a recovering addict and i still couldn't figure out all the how's and why's of my ah's behavior. keep the focus on you and it will get better, i promise. you are in my prayers.