The world is so fucked

All I try to do is help people. It's what I live for but this girl I don't know starting messaging me saying she needed someone and that she wanted to kill herself. So like the person I strive to be I reached out to her and tried to help but after se hounded me for pictures of my biggest insecurities( my belly with stretch marks from where I lost my baby from being raped when I was 16) she told me she was going to kill herself anyways and if I would cut myself, she wouldn't. I have been clean over two weeks which is a lot for me and it tore me apart because I felt taken advantage of. I was trying to help and she just wanted to hurt someone else. She told me if I didn't comply she would post my pictures on Facebook with my kik to get people to send me nasty messages before she killed herself. I had to block her but now I feel guilty and selfish and I'm sitting here crying and feeling like a terrible person.. I just needed a friend.. But now I just wish I were dead.