I'm sure your situation feels very perilous and creates anxiety in you, but reacting to that anxiety is your own worst enemy. I truly believe you are best served by taking a long term view and not getting caught up in your W's ups and downs -- just ride it out with an eye on the horizon.
I don't believe that most long term spouses would say they are "deeply in love" with their spouse, or that they are "madly attracted" to their spouse. In fact, the average long term married couple probably spends very little time evaluating their feelings for their spouse. They'll react to their needs not being met, but I doubt they pull out the "how in love am I" scale very often if ever. That's not realistic in a long term marriage and there are many reasons for it, and I think you understand that.
You want W to profess that love and "feel it" to compensate for the fact that she had an EA and placed her affections elsewhere. If she comes back to feeling in love with you and attracted to you, you can relax again and enjoy your marriage without feeling like you're leaning back in a chair.
If you make her strong feelings for you a focus, it reinforces her belief that her feelings aren't there and should be. If you take your eye off that ball, *over time* her attention to it will diminish as well. What you focus on expands, and right now the two of you are too focused on her feelings. Given time you *will* both climb out of this valley and achieve a new normal, hopefully much better than the one you had before. The more you focus on this "lack of attraction" issue now, the longer it will delay climbing back out.
Adopt the Popeye philosophy: "I am what I am and that's all that I am". If you're the best man you can be, you can't go wrong with that.
Married 18, Together 20, Now Divorced M: 48, W: 50, D: 18, S: 16, D: 12 Bomb Dropped (EA, D): 7/13/11 Start Reconcile: 8/15/11 Bomb Dropped (EA, D): 5/1/2014 (Divorced) In a New Relationship: 3/2015