It happened to me too. Love is something strange, it is something that cannot be controlled. We cannot press a button that can make someone loves us. We can only give more love and maybe that person will love us back. However sometimes it does not happen the way we want it to be. Just take it; everything happened for a reason.
if u love her, u sld luv to see her happy.
if she is happy w/o you, u sld be happy oso.
if only when she needs support, u sld gif her support w/o any intention of getting back anytink.
but neber mind, since u wan b with her, and make her sad, then u dun luv her.