There are plenty of people here who can empathize with your sitch, so please don't feel bad. You are seeking help, and that is good.
I'll keep this short because I have to scoot. Change can and will occur, it just comes slowly. So tie a nice secure knot at the end of your rope, and dig in for the long haul.
Pick up the book, 'The Superior Man,' by David Deida, and read it cover to cover.
Your wife, to me, sounds like she is emotionally and physcially exhausted. I'd check into the possibility of anti-depressants. This isn't going to help her sex drive, certainly, but her mood must change before anything else can.
You may also want to look at Peace Between the Sheets. I'm not advocating a non-orgasm sex life, but it has wonderful suggestions on how to reconnect physcially (without necessarily putting pressure on her for sex). Your emotional bond is shot, and it will take some time to rebuild it.
I'd also suggest some individual counseling for both of you. If she won't go, I'd go for you. You are at the end of your rope as well, and you must find hope and positive feelings somewhere in order to maintain your patience. It's a great way to go.
