Sooner, I don't know what it takes to get the low desire spouse to wake up. I don't want to confirm your fears, but for me I am certain nothing would have changed if I hadn't been ready to walk out the door. I had spent the last 8 years afraid of divorce. My wife had threatened it numerous times over the years and played that trump card to get her way on the big arguments. When I decided 2 months ago that I was no longer afraid of the "big D" (after all I survived it once before) it was very liberating to me. I really didn't want a divorce since that wouldn't be a good thing for the kids, but if that's what it was going to come to then so be it. The way it seems to me, the fact that I could walk away gave me the strength to make our R much better than it had ever been. Kind of the "negotiate from a position of strength instead of weakness" philosophy. I'm not claiming success yet but it seems to be working so far.
As for the performance issue, I think that's another thing the low desire W doesn't understand. When its been so long, and you are thinking to yourself "I can't believe this is finally happening!" its pretty difficult to have any staying power.
The most important thing a father can do for his children is to love their mother.