I have no idea what to do

There's this girl who I really love but she's leaving at the end of the school year I have no idea how to tell her or even what to say I just don't want her to leave but she doesn't really like me in any other way then being a friend I always try to be thereleased for her and give her someone to talk to when she needs it but since my best friend broke her heart shes still a friend but we're not as close as we were before