Tired of waiting need advice ....!

Its been 12 years that I'm chasing only one girl in my life. I love her more than words can say. But I never told her about that. She is my classmate since 14 years. This year on my birthday every thing was good and she send me a birthday card on facebook after 3 years she wished me. I was dam happy. She enjoyed talking to me but suddenly after a month she started ignoring me. I sent her a message on fb to enquire about the class and she deleted me from her friend list. I wanted to talk to her but she said never talk to me again. I am very upset about her benaviour. 5 months had passed and I had not approached her. The main problem is that I want only her and I dont even talk to any other girl. Her silence hurts badly. All my friends advice me to leave that girl but my heart doesnt allow me. Please tell me what to do. She is ignoring me badly. When I want to talk she just runs away. I dont know what to do. I changed my carrer for her. My whole life has become complicated. Thanks in advance for any help ....!

Please listen to your friends, you need to move on and forget this girl, it sounds so mean to say it but your wasting your life on something that to be honest is never gonna be. It's very hard to move on, but you need to try for your own sake, you deserve to be with someone who loves you and wants to be with you, there is someone out there for everyone, believe me. All the best xx