It's important to realize that no matter how much you care about a person, when you feel like you are the only one who cares, let it go. It may hurt but open your eye to see the people around you that love you and concentrate on enjoying them and giving them the love they deserve instead of wondering what you did to make that one jerk treat you so badly.
Even though you may feel like you are losing someone, God has sent someone to replace the void you think will be there when you let go of the hurtful relationship. Enjoy what you have instead of trying to force something that isn't going to work out. You'll feel better about it in the end.
After all, God doesn't make mistakes and it is not our place to question. We must have faith and accept things as they are because honestly we may never know why and we are probably better off not knowing.