I don't know

It is long, please bear it. I saw a girl at the beginning of my college. I liked her. She was not my classmate, then I felt I got attracted to her. She was really beautiful. I told my friends I liked a girl. The problem was the news spread fast and it reached her before I told her. So I decided let me wait for some time, if I like her after that I will ask her, if I forget it is for good. I waited for 1 year, by this time I really liked her. Got to know more about her, her interests through mutual friends but I had never talked to her in that time. Suddenly Someday it felt I should propose, so approached her. She said she is more interested in studies and we can be friends. But after that she did not talk to me much, I just talking to her once in a while and wishing for her birthday. This went on for a year and I felt I really liked her so started to chat for which she was responding but when I asked her out she rejected it. Then a couple of months later she started flirting my friend. He was a good friend of mine, so he was telling me everything. A few months later my friend said she might like him and he wants to propose her. I said if she likes you go ahead and do. A few days later He proposed but she rejected it without telling any reason. A few days later we got to know another guy proposed her and she had accepted. A year passed by and I wished for her birthday and a few months were left for college end, So I decide d to talk to her before that and I said how I feel and she said she likes me but cannot treat me as her love. So she told me to forget her and move on with my life. I wished everything goes well for her and left. After the college got over, I did not contact her for a few months and after around 9 months my friends say her marriage is fixed with a NRI. It was an arranged marriage. She told her parents about her love and they denying and forcefully convincing her for the marriage. I called her that night and asked she is fine. She said she is fine. I could not do anything. A month later I called her and met her for her birthday. She invited me for marriage there. I went to her marriage 3 months later and wished her. A couple of weeks later they left the country. I did not have her contact number there, so a couple of months later I contacted her through facebook, she said she likes that place. We had some simple conversations. About six months later, I asked her we could be friends, she said she does not want to be my friend. Then I started to message once in a while, she responds but she is not doing whole heartedly. I know friendship after marriage is not good, but I could never forget her all through these years. I always liked her and I have never thought of any other girl like that. I want to be her friend for the rest of my life. Now after graduating I applied for masters and got seat in a prestigious university. From few months I am thinking all day about her( but I am not troubling her) and my concentration levels have reduced and studies have reduced in this semester. I do not care much about studies but I feel like I am not able to get either of them. I am not able to get close to her as a friend and I don't know what else to tell. Any suggestions are welcome Thank you