Weed has always been my drug of choice too, I started using it around the same age as you and I'm 26 now. I found that life is a lot more complex than I believed it to be when I was your age. It's never too late to start college, why not apply and continue to work at the ice cream place on the side? A lot of people do that, myself included.
In my experience, when you use drugs you narrow life down to a very limited scope of options. When you're sober you get to experience everything.