Psy, It is very hurtful to have someone walk out of your life. I am not sure about your entire story with her but they are all the same when it comes to your heart.

Let go and I know that is hard. But calling and begging her will only make you feel worse in the end.
Easy for me to say, but I have been there I am sure all of us have at one time or another. You can do this and surrive. ((((hugs))))