Hmm... what is "save my marriage" DBing exactly compared to "save myself" DB? Does the first one involve more interaction with your S, actively changing things he/she said they were unhappy about, whereas the second is more leaving them alone and changing things about you? If so, then yes, I do wonder if I had tried harder at the first one if things would be different. Then again, I think I was doing that for the first 6 months when I lived at home. It's hard to do the "save my marriage" DB when the other person is making zero effort or has no inclination or interest in making changes (and particularly hard w/out kids so there's no reason to reach out to the other person!)
Me:30 H:29, no kids T:12, M:4 (when D was final) 12/13: "Don't think I want to be M anymore" 6/14: Separated (I move) 1/15: H filed for D 5/15: D final