This is very familiar to me. I have spent much of my 20s drunk. Now, in my mid 40s, I have become the dude who gets a coke or tea or coffee. In science fiction conventions, much of the socializing tends to take place at the bar. Last year, at worldcon, I did my own counter programming to that by setting up meets with people at the cafe. The evening may be a little less fun, but the next morning is so much nicer.