Wow, Rooskers, hang in there. Is there any way you could get the therapist to speak directly with your XW? I have a friend whose D11 is having a really difficult time stemming in great part to his XW's new H, D11 doesn't want to be at the XW's house anymore (they have 50/50 custody), etc. The therapist insisted on meeting with all four co-parents to talk about the situation which was a lot more helpful than my friend trying to tell his XW that her H was not being supportive enough to the D11... anyway, it might help to take you out of the communication loop with the therapist so that your XW can't accuse you of anything.
Me (46) H (42) M:14 T:18, D9 & D11 4/19 - 12/19: series of escalating BDs 9/20 - present: R and piecing