I'm sorry and it's mainly on the kids' behalf because I know you'll be fine (and I know you'll do your best to make things fine for your kids as well). Being here this long I'm a realist. Newcomers don't want to hear that their marriage wasn't good in the first place and that even saving their marriage may not result in all this wonderful stuff they envision. I know you gave this your best shot, but it doesn't really take one to tango and sometimes just getting back together isn't enough, especially when you are the one doing all the giving. I just don't think that retrovaille and DB and the hundreds of books on the subject of relationships can fix every marriage, or should.
I wish you the best. I hope you get through the divorce process amicably and are able to work out the best possible system for your kids. And I hope when you are ready that you find someone that is able to give more of themselves.
You cannot be lonely if you like the person you're alone with. Dr. Wayne Dyer