First, you need to realize that you are having an affair ... yes, a bonafide affair. Don't trick yourself into thinking just because no sex was involved that it is not an affair. That being said, the level of your affair is one from which you have a good chance of recovering your marriage. Whatever you do, don't go any farther, and set your mind to make a break with OM. You MUST do this, or your M has NO chance of recovering.
Second, you need to create a framework from which you can repair your M. I see in you a lot of the same attitudes I had just after my A. A good starter book is "His Needs, Her Needs" by Harley. I highly recommend it to you.
Chrome
"Recollect me darlin, raise me to your lips, two undernourished egos, four rotating hips"