Lynn, Dude... slow down. Time to regroup. Re-read DB or DR. You are spending way too much valuable time trying to pin down a moving target. MLC? Are you kidding? I would accept identity crisis maybe but not Mid life. Stop trying to put your current circumstances into a neat little box with a label on it. Go piss in the wind for the same result. You say you do not want to be divorced and if you really feel that way don't bring it up, least of all to her. Surely you know what a self fulfilling prophecy is.
Get back up on that mountain of yours and focus on YOU. While up there imagine the time line of Lynn on the horizon. Find the spot where YOU went off the tracks. The sooner you can get yourself grounded the sooner you can make effective changes that will attract her back to you. It is simple after all. You are desperately searching for the key piece of the puzzle you just forgot to look in the mirror.
