Your self-awareness is admirable. When I was 24, I was in the exact situation as you, with only addicts of all kinds for friends and me deciding to quit it all. I wish I could tell you that there is a positive road for getting out of that, but for me there wasn't. I no longer have any of those friends, and most, if not all are still (15 or so years later), have gone seriously downhill and are leading lives of desperation.

I don't have a lot of friends now, but the ones I have are based on true connection and mutual love and support. If your primary connection is the addiction-fueled event (i.e. going to parties and bars and such), then there isn't nearly as much of a connection as you'd think. It is terrifying to think of leaving that all behind, but you know exactly where that life is headed. You are not wrong in either choice, it is your life afterall, but you know where help is to be had if you need it.

Good luck.