I did not stop drinking at 21. I have been struggling with that substance for 3 decades, right know I am just thinking why did you bother, why not leave it alone. Insane to use so many years on this struggle that in reality did not bring anything good.
I recognize your feeling of overhvelmed sadnes saying farwell to alcohol, I do not have that now but I do remember having that feeling in the past. Even though it was bad for me, there was also an element of grief saying farwell.
I think you are right in taking it one day at the time.
Take care and be strong.