Hang in there. No matter how detached someone is, there are moments that symbolically move the sitch along toward D that trigger sadness & loss. I suspect both you and your W will go home and shed tears after signing the D agreement, if it comes to that. It is still a loss, and it needs to be mourned if you are to process it an not get stuck. Allow yourself some of that.

What your detachment is, in big part, is to not be so tied to her that her actions trigger you to react with words and actions of your own that worsen the situation. You succeeded. So, don't view it as a failure of detachment. It isn't a failure in anyway, even though it may feel like one.

Hang in there.

Me: 50 W:43
S6, S3
M: 12 yrs. T: 17
M is bad & Not happy Bomb Mar '14
S 5 Feb '15
D Bomb 13 Apr '15 (but "no hurry")
DB Coach May '15
Wants proceed on D Aug '15
Starting 1-on-1 negotiations Sept '15