You have been with this girl for 5 years and that would mean you were with her when you were 15 so that leads me to think she was your first love. Those are always sweet and precious rarely works out. She also was very young, that right there tells me that it lasted longer than most.

My advice is to let it go, you can drive yourself crazy and never find the answer you are looking for and in the end it doesn't really matter.
I know that sounds harsh I am sorry for it. Take some time to find out who you are and your own identity with an s/o.
You are young I would say date a bit different young women. Take the time to heal and work thru the grief.

Why she wouldn't talk to you, well that could be many reason's. One thing you need to search for is to find out if you are approachable or not. If you aren't then get that way.

Good luck

Move foreward not backward.

Backwards is only good if your racing a cop down hilltop.

I appreciate you saying that, I really needed someone to let me know how or could handle things and you have cleared my mind

That's EXACTLY what I said when my first broke up with me. I was with her for almost 4 years and all of the sudden I was "too immature". All I can say is it's very hard to get past, but it's completely easier if you just move on. I cried about it FOREVER and I think I probably seemed like a stalker, but once I got past her it made every other relationship that much easier. I learned from that experience, and you will too.

It will all work out...time heals all...

Babe, forget her..move on.
She does not hate you, but she has moved on.
Moving on is soo much easier than stressing about it. Takes less energy..just maybe a little bit more initial effort.:P
I know it is hard. Been there done that.

Hey Lost, don't worry too much about why she left. It's not worth it. Move on, date other people who do not remind you of her. Always remember, all you have is time. Use it to move forward with yourself, before you know it the time you shared with her will just be a memory. If you do it right that memory won't remind you of hurt.
Feel better, and good luck to you.

thanks for the help, I have moved on and have met someone and it feels good

That seems fast. I'd be cautious with the rebound off the get-go though.