It sounds a lot like a MLC to me and very much like my situation. I suggest really reading other people's stories on this board and asking for opinions/assistance.
M: 39 W: 39 Kids (3): S10; S8; D4 Married 14 years Togethor: 18 years Wife's Weird Behavior Started: 2nd Half of 2009 Bomb Dropped (about being "so done"): 2/17/10 Current Status: In counseling