I feel your pain. It is hard to see the one you love run the other way.
All I know is that by me trying to focus on becoming the kind of person I want to be has helped. Additionally, realizing that at least in my opinion, it says a lot about a person that wants to leave a marriage with children and not even consider working it out. I can understand if I where beating, cheating or some other distructive thing, however, that is not the case. Even in those circumstances it can be fixed. After all I made the commitment "till death do we part". The DR book has helped me turn things around a little..... In all circumstances I reveal that I'm content, happy and enjoying life more than ever, even when my heart is breaking. I don't ask where she is going, what she is doing, I work, help keep the house clean, love on my kids and read books like DR.
Lastly, the more I have thought about it, if my wife where to leave, I would have zero respect for Her. It would be similar to a stranger coming up to my kids and hurting them. Having said, that, I will still walk in love, be nice, not turn the children agaisnt Her and do my best to walk in forgiveness and free from bitterness. I can't help believe that there are women out there that have been walked out on or are lonely and would love to have at least a friendship with the changed man that I am. I'm not being prideful, just acknowledging that just because I'm being rejected doesn't mean my life is over. God is able to do exceedingly and abundant far more than I can ask or think, so if my wife would be willing to accept that and work with me, I truly believe our best years are to come.
Again, keep your head up, read DR and focus on making changes to yourself. The best thing you can do is to believe in yourself, and know, you are not the only one being rejected. If you can have a clear conscience that you have done everything within your power to make it work that is all you can do.
Sorry for rambeling. Love does not count up the hurtful things a wife is doing, it doesn't ask the wife to do what it wants, it believes in all things, hopes in all things and it "NEVER" fails.
So that tells me if you and I walk in LOVE.. we win or succeed.