Her question about your "Stuff" when she asked if it was "good or bad" stuff wasn't prying. She was trying to show concern if something was amiss in your life, and support if there was something good or positive happening. But you were mildly rude by saying "just stuff". It equals "mind your own business" and indeed that was what you were feeling. So then she left, not surprisingly. That interaction alone would have been off putting and that one was on you.
I don't know the whole situation but there's a lot of anger coming from you, which is not detachment.
Sorry I have not read your whole thread so maybe I'm missing some terrible things she's done. But that's how I saw that day.
M: 57 H: 60 M: 35 yrs S30,D28,D19 H off to Alaska 2006 Recon 7/07- 8/08 *2016* X = "ALASKA 2.0" GROUND HOG DAY I File D 10/16 OW DIV 2/26/2018 X marries OW 5/2016