I've been wrestling with this one for a few months. After we seemed to move into piecing mode, it seemed like it only got harder. Now everything was a, "I'm done, I have nothing left to give" type response.
I think ultimately, the why I do it is for me. The staying part of that doing, I do for my kids. I know what it's like to see my father leave..., repeatedly. To here the fighting, no about his other women. All that crap, I don't want my children dealing with that. So I keep staying as part of my doing for myself. That much of it is important to me, whether it's important to her or not is another story all together.