how?

so a friend of mine is feeling deppressed,
as a close friend i feel like a failure, as i am unable to do anthing to help.i hope my advice today was enough. i hope that she will call me anytime she's feeling sad.
i hope that i can do my best to make her happier.
through our conversations, she has made me feel as if i need to do something.
not only for her, but myself. maybe i need to try and fix my own problems first, before i help others.
maybe i need to repair the line that has been broken.
but how? and where do i begin?