How should i proceed to get my lover back?

hai guys..i love a grils from my 10th std and it has been 6yrs now....v used to meet in our church ....i finished bsc and am planning to go for higher studies...my lover is doing mbbs now....i proposed her 2yrs before but she said dat all these things wont help us in de long run....but for de past 3 months she was in love wit her clmmate and she has dropped it bec of her parent's compelsion...after dat i asked her whether she ll accept me if come through her parents but she said since she already had a relation but dropped now, she is not interested in another....later she said dat she cant think me in any other way other than a good friend....but am so much fixed to her dat i want her as my life....can u tell me how can i convince her or how should i move forward to succeed in my love plz...