Thank you everyone! I'm still very frustrated about not being able to do anything but it was helpful getting your opinions and support...
I didn't bring her wine to the office and I try not to enable her habits, but I've never told her directly that I refuse to do it. I'm scared of how she might react. I usually say that I don't have any money or that there were no shops on the way; sometimes I won't come home for the night just to avoid buying her alcohol and cigarettes (we've been living together for the past two months but I'm moving out in a week).
I'm thinking about asking all of our close friends to stop enabling her behaviour as well, but as I said before, I'm scared of how she'll react, especially because she's depressed and has had suicidal tendencies in the past...