Online Infatuation

Hello Sir/Madam,
I 20 years old male...I am an engineering student from one of the best engineering colleges of my country. Getting into my college is very tough, so we hardly have girls in our college. Its like 1 girl per 15 guys. n Girls r also not good looking.So only way to interact with girls is online-friendship.
I added a girl year back on a social-networkin website.we used to ve pretty decent chat then.I used to flirt with her and she also did like it.
Then I became busy with my life and she with her, and we rarely used to chat.Few months ago, One nite, while chatting She made me feel like her friend, as if she knows me well and cares for me. From that day , I started founding her the world's prettiest girl. I started liking her like crazy.
But knowing that our friendship is just online and it cant grow to love-affair, one day I sat down n poured all my feelings in a mail and bid her good-bye and also gave her my number in that mail. She dint reply but one week later I got a message , It was her message telling that its her no.
I used to send her Good-morning Good-nite messages, some were friendship msg.s , some jokes, etc.Then we used to have chit-chat on mobiles. But whenever I used to call her, she never used to pick it up.So iasked her when can I call you, she said 'I dont know'.
Feeling broken hearted, I just told her that why is she passing time with me and playing with me. She replied that 'WTF, am I taling'
I got more shocked when I saw her saying 'I LOve You' to some boys at different wall-posts.I ,sarcastically asked her if all were her brothers..she replied that they all are her best-friends and asked me to my mind my own matters.
She says she is an emo, she never wants to marry in her life, world is fake and blah blah.
WHAT TO DO NOW..??? I STILL LIKE HER.. :( ..I DONT KNOW WHY AM I LOWERING MY SELF_ESTEEM BY STILL TRYING ON HER>>>>PLEASE HELP..I BEG YOU ..