I think a large part of anxiousness - maybe even all of it? - is anticipation of what *might* happen, rather than of what's happening in the moment.
you've already proved to yourself on a previous trip that when you were actually there, you were fine, so why be anxious about the next trip? I know it's easier said than done, but try to stay in the "now" & don't project all the "what if's?" into the future. make the decision that you aren't going to drink & plan what fun you're going to have on your trip
