I was a lot older than 17 when I quit but I had to make some changes to my life - I really wanted something different, and you can't do that without making changes IMO.
I changed some friends and took myself out of social occasions that centered around alcohol until I felt I was secure in my commitment to staying sober.
It was that important to me.
I still don't regret doing that - it was a great foundation for my continued recovery
D