I've been catching up on your situation, so painful to read, you have my sympathies. My sister just got a D, and the L will advise that you never move out for two reasons (1) your W can spin this into an abandonment claim WRT the girls and custody, and (2) if she wants you out, the longer you stay, the more leverage you will have in a D settlement. That said, don't give up!
My situation involved an OM as I said, and I also suspect OM based on your wife's actions. It so hard to believe that she would be distant and disengaged for so long without someone else involved. If she has someone else who is making her feel loved, then she's getting the support she needs to act this way. Either that or she's just super cold, and if that's the case, you would have known that about her.
I read a couple great things lately that helped me. One is that the "in love" feeling that your wife refers to is always temporary. It lasts from months to years, but generally not more than 2 years. The "in love" feeling alters your brain chemistry, and makes you overlook the flaws of your lover. After that wears off, your spouses flaws start to bother you, and love becomes work. That's the brutal reality of it.
From that point, to the degree you are both getting your needs met, you will be motivated to do the work to keep things going. Part of that motivation is feeling loved by the other person. I recommend reading "The 5 Love Languages" if you have not done so already, very eye-opening. If your needs are not being met in the way you need them met, eventually you will get increasingly desperate / unhappy and one outlet for that is an affair, another is divorce / separation, or resigning yourself to misery.
If you haven't yet, check out the book, it could really help your situation, or at the very least give you something productive to discuss with your W about her needs when you do MC.
--Accuray
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