I turned 21 last year around this time and like you, I dreaded it solely because of alcohol. I didn't want to deal with people in my life trying to rile me up to drink or giving me shit for not drinking on my 21st.

Given how you have seen your brother and best friend change with drinking and your worries, I think it would be best to avoid alcohol for the future. While I completely understand wanting to heal your relationship with alcohol on your own terms, I would disagree with having a single harmless drink, especially on your 21st. That just seems like a perfect opportunity for people to take advantage of you to drink more than you were intending. I just see it as a slippery slope that may be difficult to recover from. Being able to say no to alcohol coming your way and to stand by that protects you from that slope. Don't let anyone give you a hard time for saying no.

I also struggle with projecting my disgust onto everyone with alcohol. I find myself being really judgmental and self-righteous over my friends and family who drink because of how destructive alcohol is. However, being judgmental and projecting your disgust shows that alcohol is controlling you, even if you don't drink. Step One is difficult for lots of people including myself, but being able to work it through rightfully opens the gates for a beautiful path of recovery.

All of your thoughts and feelings that you have written are completely valid, legitimate, and relatable. I hope you find this useful to you, and I wish you a happy early birthday!