Struggles with relationships are often our best teachers and spur us to do something that allows growth. The growth isn't an indicator that the one should therefore ditch the relationship - as all relationships are work and have struggles that can stimulate growth - but one of the challenges is that if you get the opportunity to patch it back together it will be much stronger if you can figure out a way to allow both of you to continue to grow within the R. I hope you get that opportunity, but it is great that you can see what you have gained out of the hard struggle itself.
I agree that the cancellation of this meeting may have been a very good thing for you, both in terms of your well-being (you were driving yourself a bit nuts) and your ability to detach and be effective at DBing. It was fairly clear that your W was not really ready to work on things, and the MC was premature. I'm hopeful that her cancelling turns out to be a blessing in disguise no matter who difficult it was to have her do that.
Keep strong and good work!
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