If I had to guess, your approach to playing now is to see if you'll play as well as you did before. You might be starting with a question, "how crap will I play today?"
When you play, try to watch yourself. It wouldn't surprise me if, when you miss a shot, you're already standing up, shrugging indignantly at your teammates and spectators. Playing like that is no fun. You're constantly measuring the delta between old expectations and results. Anticipating and pre-apologizing.
I also bet, after a couple drinks you have no problem getting your head in the box and just playing, without expectations and with sheer enjoyment of the game.
You might try being really careful about staying in the box. Try to keep quiet and not talk too much for a half hour before you play. When warming up, just watch what happens without expectation or judgement. Just let your body/mind see what it needs to see and fix what it needs to fix until you come into stroke. Try keeping soft eyes on the table when you are playing, and try to keep words out of your mind. If you find yourself talking to yourself or others, don't get mad, just slowly move your focus back to the table. The hardest part of this game is getting your thinking/talking mind out of the way. A couple of beers helps, but there are lots of ways to get there.
Best of luck to you. Your game is still in there. A Tito's rocks doesn't know how to play pool.