Worried about ex-girlfriend

Good Morning (or afternoon for some)
This is my first time asking for advice on a forum so I'll try to give you as much detail as I can.
I used to be in a long distance relationship that lasted a year with a girl 4 years younger than I am (I am nearly 22). It started off as playing a few games, talking and sharing secrets then it became what it became. This relationship was great, we were always happy to talk to the other, spending our free time "together" despite the distance. We were planning a meeting as well. (5000 miles separates us).
Sadly, after some arguments and screams during chat and games, she decided to break up for good. She did say she wanted to stay friend and didn't want to lose me at all. I played along.
Though, she stopped talking to me and started spending time with other people online ( a group of friends in common) and told me how easy it was to be friends with them.
So I did some no contact stupidity, send her some messages to initiate some contact and all the various stuff that you can see on forums.
None of it worked, friendship is to a stand still.
But there is one thing I worry about and it's her health. She always had a weak immune system and health problem, she used to smoke, drink, cut herself. I managed to make her stop all of it.
But now she started again, everyday, and is even talking about taking drugs if she could get it (hard in her country). Despite telling her that it's bad for her and that she never wanted to do this stuff, I was answered the following:
"Just because I never talked about it doesn't mean I never thought or wanted to do it. It's what I want. At this age we all go badass, if not now then when ? You can't understand since you've done none of these".
The problem is, this girl means a lot to me, and all that's happening is bad for her.
She barely talks to anyone (confirmed by her friends), she lets problem get to her, she stopped caring about everything...
I thought I took the break up badly, but it seems it's even worse for her and she tells herself that's what she wants.
Some would say I shouldn't care, but I just can't live with myself knowing a girl that meant so much to me do this to herself.
What can I do for to accept my help without pushing her ? How can I make her understand that no, things aren't alright and that she has problems.
Of course I should mention that the one guy she talked to a lot lately is drinking, smoking and drugging himself a lot and despite not saying he hasn't got a hand in it, I really don't think he'll be one to tell her not to do all this.
She's often wasted and she stopped caring. And as much as I told myself that we won't be together, I still worry about her well being.
Sorry to bother you with my story, but I just can't let that girl in this state, I'd never forgive myself for it.