Inaspin - Sorry to hear your MC was less than even you suspected, but don't be too hard on yourself for backsliding, EVERYONE backslides, it really can't be helped sometimes. BUT...pick yourself up, dust yourself off and climb back on the horse...and try not to let it happen again (though it will).
Also, you need to understand that with your W in La-La-Land, nothing you do is going to "snap" her out of it. IF (and it's a big one) she comes out of it (most eventually do), it will be in her own time and your actions don't affect the timeline much.
Seems like our LBS actions easily make things worse (like fuel on a fire) but are much less effective at making things better. So, as others have recommended, detaching and remaining calm and neutral at least takes away fuel from their fire and prevents them from further justifying their decision to leave.
There is no easy answer here, unfortunately. Hang tough.
Me 47 W 44 D16, D13 T 23yrs M 20yrs WAW/MLC + Male EA "BFF from H.S." = Misery