I worked at a headshop in my youth and I had a similar experience. Once I started seeing what drugs were doing to the customers I didn't want to be a part of it anymore.

I am a former drug addict and these days I deal with alcoholism. I don't think I could ever be content with sobriety, there's just a part of me that's not satisfied otherwise. The trick is trying to stay in moderation. It works sometimes, not so well others. It's something I just have to deal with.

So I get how these people feel, but it doesn't mean I want to contribute to it.