Why do we need friends for?

A lot has been and is still written on friendship - good and dreamy things. Friends standby you throughout the thick and thin, friends love u the way u are, friends are better than ur siblings… And the glorious words go on and on.

A recent happening, I would rather term it as a mishap, has actually made me think on the sanctity of these thoughts. I will give a brief background - one of my friends (a very close friend of past 5-6 years) is on a self destructive way. She is in hibernation these days, trying to shy away from people who try to help her and try to jolt her back to her senses. For past two years, I have been a subtle, yet a solid support to her. Worried about her, prayed for her, thought for her….but the day I thought I was not being a friend enough, that I need to tell her what she was doing to herself was actually wrong..she severed all ties with me. She stopped responding to my calls, emails, messages…

My fault? I honestly told her that she needs to get out of her shell, make some compromises with her life and go on with her life. But I ended up losing one of my real good friends. Miss her even now.

My question is:

Was I wrong in being truthful?
Had I been good enough for her if I were the indifferent kind of so-called friend? Kind of those friends who show fake concern on face and don’t even spare a single thought on your back.
Couldn't she come upfront and tell me that “hey I did not like it?’?
Didn't our relationship worth a second chance or a hurt (that I might have caused to her unknowingly)?
If I didn’t tell her the truth on her face, wasn’t I like any other stranger?
What would have she done if her sister or daughter was going the wrong way in her life?

I don’t want her back in my life. Though I miss her terribly...she was like a younger sister to me. But she has done irreparable damage to me.

She made me extra cautious with other friends. I guess I am now being skeptical about each friend of mine, or I would say I have lost that unfailing trust that ppl have about their friends.