Since the comments were closed on your bitch for some reason, I figured this was the next best way to respond.
You did good, kid - real good. Holding your head up in the presence of a lover-turned-enemy is hard, but you did it anyway. You've learned two things with that episode: the kind of person you are, and the kind of person he is. It's killing him that you're moving on - that's why he showed up with the new GF, to watch the fireworks and to validate himself as a sex god for whose attention combat is justified. You've not only seen him for the attention-whore he is, you also thwarted his machinations to bring you to heel through jealousy.
You're brilliant, you're strong. You will get through this. Your life will get better. I promise. —A Coast Reader