I 'm so confused 

The stbx IM'd me last night from out of town. Is the girlfriend not spending enough time online with him? Is he bored? Am I just a way to fill in some time for him? Does he miss me now that he isn't seeing her everyday at work? We IM'd for about 45 minutes and then spent about another hour on the phone together. I cried, I begged him (even though I said I never would again) to consider saving us. I begged him not to let her ruin him even if he decides he doesn't want to be with me. We actually talked some, like we haven't in at least the last 3 years of our marriage. He apologizes alot but that doesn't mean a whole lot when I still hurt and he still does things to hurt me, even if he doesn't mean to. Why does he continue to reach out to me if what we had is not worth saving? Why can't I just let him go and not keep trying to save it? I know better, I really do but can't seem to stop myself. Why do I care if she ruins him? Shouldn't I be like, "he will get whatever he deserves". Sometimes I do feel that way, but deep down where it really matters, I do not want to see him fail. Why would I continue to ask him to not let us go when I feel that deep down, he will never put in the effort needed? I wish I knew. I wish I could just stop doing this to myself. I wish I didn't take every little sign as hope that he regrets what he has done. Why can't I keep that resolve there to just let him go on about his life and I just worry about mine? Maybe it was my upbringing that you just don't get divorced. Sometimes I feel like the 6 month waiting period for the divorce is dragging by and at others I feel like it is flying by way too quickly. I miss my best friend. That man has been my best friend for the last 19 years. That man, other than what he has done to me now, has always been an honorable man with integrity. That is why this all blows me away. If he had always been a jackass then it would be easier, I think. I only want the chance to go to counseling and see if it really has to be over. I have a cold and don't feel well so I know that has weakened my defenses. I just wish I could keep all of this straight and set a path and stick to it. I hate being wishy washy. He says he listens to everything I say. He says he will think about things while he is out there. He says that after he gets back and then I later get back from school, we will sit down and talk. I told him that if she dumps him, I will always feel second best if he comes back to try then. I told him it would mean more to me if I saw it was him making the decision to walk away from her to try. Does that make sense? Help. I just need to get my head back on straight.