And her reason for ending her sessions with the eminent therapist was...?
I wouldn't actually recommend reading PM unless you reach a point where you feel the compelling need to CHANGE your life. At the moment, I think, you're indicating that you've tried everything, that your wife has painted you into a corner and you have no choice except to seek sex outside M. If you reach a breaking point where you can no longer tolerate your compromises, that would be the time to reach for PM.