Figuring why our relationships tend to fail, or why a pattern seems to recur is very helpful.
In other words, "What's wrong with me? How do I fix it? How do I become whole again?"
For me, finding a good cognitive behavioral therapist was a big help in showing me my pathologies. I also took an MMPI (abnormal psych test) which brought some interesting things to light.
In addition, I found a book called No More Mr Nice Guy, which is aimed at men, but nailed about 75% of my issues with some helpful exercizes.
There's really no point obsessing over the relationship, Hoosier -- it's over. There are the anger and abandonment issues, and, perhaps, making sure you set a fair schedule for your daughter seeing your ex. That's about it.
The injustice of it all you can only deal with by working that though with God. In the end, he is your ex's judge. Nothing escapes his gaze.