What do you think of me falling off the wagon tonight?
What happened, and why and when did this occur?
I have been on a path to sobriety for a long time. Alcoholism has been a struggle in my family tree.
It is good to be making a solid plan to give up on alcohol if you have a problem.  It can be a problem if you start drinking again after trying to quit, but there are people who can help you regain your sobriety with a little effort.
It was a slip up after having just a single beer at a party and I don't feel good. I'm going to call my sponsor tonight to see what I can do.
I think you are doing a good thing to call your sponsor because it is best to stay away from drinking.