I am a spouse that had thrown in the towel in our marriage (W was refusing attempts to work out M problems). Now I found a new ray of hope, so I thought I'd give my 2 cents.
The DB was excellent for getting me to think about who I presented to my spouse. It didn't change the fact that I couldn't understand how she responded to me in the first place.
I was recommended to read "How to Improve Your Marriage Without Talking About It". I found that a lot of my responses in our separation and before seemed to make a lot more sense as I read it. This made it possible to connect - a goal of DB.
My wife was shocked, as you and others were, when I asked for the D. I thought she wanted it, because she had talked of leaving when the kids grew up and because she was unhappy. Shielding her emotions to protect me from hurting her only made it worse. Maybe understanding your husband's reactions better would help you decide what advice in DB to follow and what to leave. He might want to read a few sections, too, as it was authored by both a man and a woman (different perspectives).
I can't say that damage of the separation for me and my W is repairable for sure, but I've got a lot more satisfaction for trying.
