- The idea that I may have been a practice round that leads him to understand his issues and he goes and gets better and some other woman gets the life that I wanted.
This one resonates with me. My first wife said pretty much exactly that to me. That she didn't want some other woman getting to live HER life (and she said this after she left me for her affair partner!)
I can sadly state that I made most of the same mistakes in my second marriage as I did in my first, and my wife left for many of the same reasons.
One thing I've learned is that people don't REALLY change unless something traumatic happens. They might modify their behavior somewhat, but underneath, they're the same. being the left behind spouse is trauma. Being an [censored] that abandons your spouse probably isn't.
You're not the practice round. You were the main event, and HE was the one who walked away from that. No one else is going to get YOUR life. They're going to get the same mess from him that you did.