Choose for yourself, but look closely to see if you want to help them "for yourself" or for them. You may be a "fixer" - you could make yourself happy if you fix them but then what? Do you want to continue the friendship? Do you want to just know that they're ok?

Sounds like you're young. As you get older, you get to the point where you say "you know, they really need to fix themselves and if they want my help, I will be there for them." I've helped one person help themself and I felt good about it. That same person isn't in my life anymore - but she's now married and in a much better place than when I knew her a few years ago. She was a horrible alcoholic, had some job issues and need to get her life straight after a failed marriage. Hard on me at the time but I wanted to "fix her" - the only way it really worked was when we worked to help her fix herself.

Good luck with you - but people come into your life for a reason and they leave for a reason. You should think to yourself if you really need everyone in your life to be ok when they come in and when they leave - or if you are ok with letting them go down their own dark-path in life without trying to fix them. You're still ok even if they're not. Your strength in yourself isn't reliant on how you fix others (at least that's how I'm thinking these days).