If there's an affair, that problem will be in the way (read TBL's posts above), but it can be dealt with.
If it is a lack of love, well I never loved my wife, but I do now.
If it is an attraction, communication, or other skill or style issue, you can work on those before Retrou on your own.
Have you read "His Needs, Her Needs" or "Improve your marriage without talking about it"? Both would help you better meet his (and your) emotional needs.
Blunt advice- Remember, he isn't getting sex from you, and that is one powerful EN. If you are willing to do it with him during the weekend, the opportunity is there at night. If he's used to using his own methods, that is one less reason to come back.
Have you spent a lot of time figuring out what things made you (and as a result him) upset during your marriage?