First off you have the patience of a saint. I don't suppose that knowing your wife has a problem and it was not all due to you, gives you a bit of solace? I admire your commitment to your M to stick it out for as long as you have. I am at nine weeks and I really do not see myself lasting past six months. I have actually circled that date on my mental calendar.
All I can really do is offer support for ya. Your sitch is terra-icognita for me (and you I guess). I am in no position to offer advice. You have been so incredibly strong for so long. I hope you can hang in there little longer.
When you think about giving up what normally prompts those feelings? Curious because I very seldom see my W and I am on the verge signing the papers and saying goodbye. My W also has some serious problems that she has never shared with anybody but me. Not even her folks or friends. Her history includes sexual assault and cutting herself when she was in her teens. She would often become very distant to me and "clam-up". I finally convinced her, after 12 years, to see a IC. The following day she left me. Last contact I had with her she was under the impression that I was the worst thing that ever happened to her. WTF? really? Still sets me back when I think about that.
Hang in there bro!
Me: 44 Bomb: 11/27/11 Divorced:6/12 Life goes on: 6/13