I have fallen for my best friend

It was something that gradually happened. i didnt like her at first but now im crazy for her. knowing that she only see me as a friend is killing me inside. i try not to act like it bothers me when she talks to me about other guys but it really does. but there something that i cant get enought from her and it her beauttiful smile and i would do anything to see her smile, to see her happy. even if it means seeing her i somone elses arms. my heart willl shater but i will try to smile and congratulate her becuase i know that would make her happy. and that all i really care about. Please guys give me some advice on how not to see her like that i just want to be her friend too but i dont have no say in what my heart feels.

i already did but she only sees me as a friend