Why does my friend think I'm a druggie?

We're both 17, and she knew I occasionally drank and smoked weed and cigarettes. I have been drinking and smoking more, but its summer. I tried x once, too. That's all, and she told me that I'm changing and just want to hang with this guy and smoke, or party. She was my shopping buddy I guess, and shes mad because I'll smoke a cigarette. Shes asked me for a cigarette before! What should I tell her? I want to be a friend, but shes getting annoying.