5 years ago i was a friend,to a girl,we talked,about everything,we had so many things in common,then I fell in love with her..she told she is not interested,and she sees me just a a brother,we stopes talking after that..now 5years later I still think of her..and I don't seem to be able to develop the same feelings for anyone else..is it normal?

But you need to move on.
Get a girlfriend and concentrate on her. Be the best boyfriend you can be! Focus on making her happy. Then when you see how much you mean to someone, you'll be very happy.