If you can't say "no" then I'd say you were addicted. I'd figure out some way to make myself say no, put all the money in the bank (saving for a car perhaps? :-) and find a friend or two who does something different or an activity in a different place. If you don't buy it, aren't around it, you can't smoke it. I'd start working on what you want "next" in your life (school, certain job, your own place, to travel, etc.)

I'd reduce the "wanting" by realizing we want lots of things all the time. I'd just "work on" something else I wanted that I thought was healthier for me.