How can i get my ex back?

My ex last night told me she wants to cut off all communication with me and said her last goodbye to me last night. I'm 16 and she's 15 we've been going out long distantly for years now we would web cam and talk on the phone/facebook so being faithful wasn't the problem what was the problem was for her having the patience to wait for me to go see her after i finish school in 2013 but she told me last night that waiting was too hard for her and she needed to find somebody from her school when it starts back up. she even told me once that i was her "one". i've tried texting her and calling her many times today and no answer at all from her. I can't just let her go I need to do something about this before it's too late please help