Speaking of betrayal?

I had a live in girlfriend for almost 3 years. March 2006 she took a government job and had to move 800 miles away. I helped set her up in the new place, and we visited each other at least once a month. Sep 2006 she announces she thinks we need to take a break, split up, as she wants to try "life on her own". Turns out she just wanted to get with another guy there and I found out she slept with him within two weeks of our split. Ouch. Anyways, now she is no longer with that guy and realizes her mistake (she did admit what she did) and would like another try with me. She now realizes that I am all she has been looking for in a man. I was very much in love, but think I was burned too bad by what she did. Thoughts?