Welcome back!!
I am much older than you, but I, too, had difficulty with the thought of "I can never get high again...ever". I don't know your HP beliefs, but I had to pray to be "willing to be willing to not want to use again". Had to do that for a while, before I realized one of the "willings" had dropped off.
When I went to meetings, I had a friend who was 19...in recovery. His dad was also an RA (recovering alcoholic), though they rarely went to the same meetings. He had started drinking young, and by 19 had realized that he was never going to be a social drinker. Come to think of it, there were SEVERAL young people in my home group.
Alcoholism/addition doesn't discriminate....it will take some down younger and faster. The good news is, you have a much better life ahead of you, without alcohol, if you want it. We think life can never be fun, again, if we're not using/drinking, but it can. It's a bit uncomfortable, at first, but it gets better.
Hugs and prayers,
Amy