teenager drama and drugs

I feel like I aged 40 years in a couple of hours. After all the stuff going on with the adults in my life a bit of teenage drama is really unnecessary, but when a friend calls me at 11 o'clock at night barely able to talk because she's so high I can't just turn her away, especially if she's at the house of the guy who tried to rape me. So of course, my loving nature and concern puts me in the middle of drama again. I had to stay on the phone with this girl until her mom showed up to pick her up. Now I'm sure she hates me though, because half way through her sentence she hung up without a word so I called her mom to make sure she was okay, and I did inform her the reason for my concern was because my friend was high in a house alone with 4 boys one of whom has a history of going to far. I felt lame. I'm a 19 year old girl I should be out hanging out with my friends not having to lecture them on drugs. I chose her as a friend specifically for the fact that her family life is alot like mine and she used to have the same views as me, but now I don't know if I can be her friend. I can't put myself through the emotional stress of worrying about her and I can't just ignore her when she needs help, but I don't want to lose a good friend....