Thanks for the update, glad you are doing okay.
If it makes you feel better, in a similar situation, the friends who dropped contact with me had been my friends first--I didn't even know they were just his until they didn't bother to check in with me. One of them was one of my best friends ever, and I miss her terribly.
I'm glad your ex is dating again. But I don't think she was fair to you when she ended things--but somehow monogamous people seem to have to convince themselves that they hate their old partner before they can allow themselves the possibility of loving someone new.
Best of luck with everything. You should probably talk to K a little about her feelings about your lesbians-in-the-woods venture. Can't hurt to ask her how she feels.