I'm so sorry to see you back here, but not surprised (see my last post to understand why).
While one always hates to say it, I think you have come to the correct conclusion that it is time to move on and walk away (it seems pretty clear she's already gone anyway). DB'ing is about creating an atmosphere where reconciliation can take place, but it is not a cure and there more stories of failure here than success because, in spite of what Ms. Weiner-Davis says, it is NOT possible for one person to save a marriage.
More accurately, one person can stop doing the things that may have driven the relationship to collapse, one person can avoid doing things that will serve to kill any reconciliation where that's possible, and one person can create an environment where love can flourish. But these are all groundwork. To be fruitful, the other person has to be willing to forgive, be engaged, take responsibility, be objective, and/or take on the hard work of finding common ground. Assuming your descriptions are accurate, your WAS has exhibited absolutely none of these required characteristics.
It is that fact, and pretty much that fact alone, that means any attempt on your part to save the marriage will likely be a Sisyphusian task (something you are already well on your way to proving beyond doubt).
I agree completely with the various posters recommending more structure for D6. With everything else falling apart, she needs that structure now more than ever at a time when separated parents are so guilt-ridden that they are almost incapable of establishing it. You are NOT doing her (or yourself or anyone else) any favors if she becomes the driver.
From someone who's been there, let me give you the most important advice you will hear. Get the best divorce attorney you can afford...now...and make sure he/she is a pit bull. Then put him/her on a leash. You don't want to turn the dogs loose yet, but you want them ready in the pen. Our legal system is an adversarial one (any lawyer will tell you that) and if you are not prepared to defend yourself with no holds barred, you're a sitting duck (because the other side will). Don't get me wrong, I'm not happy about it. But it's how the game is played and there's nothing you can do about it.
Ask what you should do to protect yourself and put yourself in the best position for a divorce. I did not do this and wound up regretting it. But let me reiterate, at this point, this is for you and you alone. Get advice so you don't make stupid mistakes, but don't take any action with respect to the relationship. Don't say anything about the attorney, don't use the D word, don't let on that you are doing anything other than just carving out a life for yourself apart from her...just like she wants.
Perhaps I'll be proved wrong (that would be nice) and you'll all get through this and you can just dump the lawyer and forget the whole thing. But if not, you'll be ready when she claims custody, alimony, and child support. If she's unemployed, she's looking for a way to fund her new lifestyle, your D6 is looking like a fat check, and you're in the cross-hairs.
Like many folks, I thought we could be "civilized" about the D...everyone go their separate way and take what was theirs with them, but that went out the door when opposing counsel went for the jugular and left me with nothing while all the time I was telling my attorney "don't hurt her".
That doesn't mean your WAW will be as bad as my X, just that you should be prepared in the event she is. As they say, hope for the best, but plan for the worst.
In the meantime, you can be proud of the fact that you stuck it out for a couple years (many don't make that) and gave her every opportunity to pursue counseling and other avenues to repair your relationship. Her failure to take advantage of them is exactly that, her failure...not yours. Be strong for your D6.
