You cannot talk or reason with your W on her choice to leave the marriage. It is her perception at this moment and she's put up a Berlin Wall between the two of you as a self-protection mechanism. She's feeling pain so she distances herself from you because of the memories, feeling helpless that you don't listen to her concerns, and probably some guilt mixed in there.
For now, let W walk her own path and figure things out by herself. What you can do is validate her when W texts you or talks to you about her emotions. You don't bring up YOUR own emotions or anything related to the marriage. Need to STFU about the marriage. It is all about W's feelings, thoughts, and emotions right now. Yep, it is a tough road which is why DB vets harp at the "detachment" point over and over for your own mental well-being and GAL to put the focus squarely back on YOU.
What GAL activities are you involved with now, BH?