Scot, sorry you are here but this is a good place to be; but I see you have 40 posts already and registered back in 10/2010 so you probably already knew that.
Certainly sounds like a MLC to me; according to your stats she is looking at 50 (as is my W); her moods and behaviors are all over the grid (as are my W's)and regardless of what you have done or said to take the high road in your marriage, you are the scum of the earth (ditto here).
Nothing you can do about her R with the OM; she is the center of her own universe right now. Patience and detachment are what most folks here will tell you, but I'll throw in my own $.02: she needs to figure out her own financial woes. IMHO, it's one thing if a spouse walks due to a MLC or some other reason; it's quite another if an OP is involved. This might be the point where "tough love" needs to be enforced.
Of course, you need to decide where that line is drawn and how it will affect your Ds. How far away from you do they all live? How much time do you spend with your Ds?
Keep posting and stay cool, calm and collected.
H 56 W 48 D27,S21 SS25 SS22 Severely autistic M(#2 for both) 9 1/2 yrs. "I've never loved you" 3/7/2011 Separated 8/7/2011 BITS