My girlfriend is now my ex...... she told me by text today?

Okay, well i met this girl off facebook, and she was really into me, she's 21 and i'm 24. So we met up, and i was worried that afer we met that she wouldnt like me as much or stop speaking to me. But it turned out she liked me more and i liked her more than i did from the pics. She lives about an hour and half from me on the train and we met most w'ends or fortnights..... she text me everyday saying she missed me, can't wait to see me, she loves being my girlfriend and that i'm her Mr right and she couldn't live with out me now, i stayed at hers and her at mine, we met eachothers parents and all got on real well and she always was wanting to be close and kiss and talk to me and we had been together 3 months when this w'end she went all quite on me....... hardly texing me and when she did not putting anything in like she misses me. And today she sent me this mive text saying - Ive been quiet cos i've been thinking alot, and i don't feel about you, the way i should, and i don't miss you as much as i should and i've been having a go at you because i don't feel like i used to about you. we spoke on the phone after and i was in so much shock, because i'm so used of her saying im the only one for her and all the other nice things. But she said she has been feeling like it for 2 weeks now and didn't know how to tell me and wanted to see if her feelings would change for me. She said she used to like me alot but it didnt progress like it should and she saw us more as friends (even tho we kissed, held hands, etc) I said but what about all the constant texting and saying you missed me and can't wait to see me - she said she said it half heartidly where she wanted to mean it. So im in shock from where she was allover me and then in a instant she is saying it's been two weeks where she don't like me like she used too. So there must be things she didnt like about me, but then i think of all the good times we had. But obviously wasnt enough. ive just got to get used to it, but it's a girl i thought id have a future with.