Well if you are in love with a person and that person don't share your love, then you will have heart sorrow for a while.
There are no easy way....we are all different ...song about the same are sung all over the world...you are not the first who have heart sorrow and will not be the last...
You must try to put the person out of your mind, I know it's more easy to say then done, but you can never force anyone to love you, and the only way you can befriend her is to treat her with respect....all other ways will fail...and then you just make a fool of yourself.
Good luck.