As I read your posting, I see myself. The only difference is, I am a woman with the same problem with my husband.
He will not talk about it, but last night I decided we had to do something. It was also a night for us that I was hoping for something, that of course led to another excuse.
I finally asked if he would compromise. No sex, just something physical. Some hugging and kissing and talking. We didn't talk about why he didn't want sex though. He was willing and I think because the pressure was off to have sex, it made him a little more at ease. I do know if the sex is going to happen any time soon, but at least we have made a start.
Do you think she would be willing to try? Or maybe you already have. I'm new here and don't know alot yet, so my advise may not be the best, but I do know exactly how you feel.
I too, want my marriage to work. We have been through so much together that I would have never thought that this is what would tear us apart.
Good Luck! And don't give up just yet. I know I'm not.