That's where making yourself a better person in the end will make all the difference in the world. It's incredibly hard but changes for the better will not push your W away. It may not pull her closer to you either (if she choses to ignore them) but the reality is there is probably someone else out there that can get to experience the "better you." Either way, it could either save your marriage and if it doesn't, you'll be a better person for the next person you are with and have a greater understanding of what it takes to have a successful relationship and/or marriage.
And that's your W's loss if she chooses to ignore that fact. You have no children so your W probably doesn't feel the "family guilt" that my W is feeling right now. I'm fortunate enough that my W came to grips with the fact that she didn't want to break up our family therefore I've been able to spend more time with her and SHOW the changes that I've made. It's made some difference, but we're not even close to out-of-the-woods. It may turn out okay, it may not. Who knows?
I find it interesting that you mentioned your W has a hard time getting over past resentments. My W is battling with the same struggle. One thing I've learned is that we can't alter what we did in the past. I know I wasn't the best husband I could be and I'm sure you could say the same thing. But what's interesting is those past events no longer have ANYTHING to do with us. Those resentments are on their shoulders, not ours. All we can do is worry about what we do from this point forward and not give them reasons to solidify those feelings of resentment even though they will look for every opportunity to do so.
That's why you have to smile, be confident, and be patient if the goal is to save your marriage.
Me: 33 W: 27 S: 5 D: 2 Bomb: 1/2/14 First Separation: 1/25/14 MC: 2/7/14 (one time only) Moved Back in: 3/31/14 W says she wants a divorce and moves out: 7/26/14 Appt to sign dissolution: 12/30/14