Your wife is not opening up. She's not willing to fight. There appears to be a long history for which she blames you and you blame yourself.
This is the longest journey that you will ever be on, but don't worry, it's called LIFE. Everyone is on it :-)
The best thing that you can do, is to let her live her life. DB'ing is about letting the other person be, whilst you deal with yourself. When things were at the worst with my ex-wayward-wife, my friend used to say "why don't you lock the door, i'd never let my wife out if she doesn't come home a respectable time". To which I said, "it is her life, i must live mine, i cannot be her, i cannot make her choices".
It's the hardest thing a man can ever do, to watch the love of his life walk away, to not be able to hear, i love you back. But it makes you a real man, a better man.
oh, and cry, cry as much as you can. There will come a day when there are no tears, that is when you know that you are healed.
and one last thing. most people recommend meds to help deal, i suggest that you take nothing. Take sick from work, lie to your friends if you must, but feel this. feel it all. It makes you feel alive.
Just cos things are going right, doesn't mean that they were always wrong.