Apparently I'm an addict, and it's ruining my life

I just went in for my annual physical, and my doctor seems a little alarmed at my liver issues. I'm 34, and I always thought that addicts were people who did hard drugs, or drank heavily. I smoke weed pretty much daily, but I thought that was fine because it's legal in my state and not supposed to be bad for you, right? I also do a little coke on weekends, but I'm not like a regular user or anything. I also take a little Xanax every now and then to calm my nerves, but I can go a few weeks without it if I have to. How do I know if I'm a addict or not? I don't feel like I'm an addict, but my doctor says I might be headed that way if I'm not careful.