Enjoy yourself. Remember - it will be a long time before peeing will be a casual thing. Fill that catheter bag to the brim! Drink up and enjoy. I certainly had a few beers and a glass of wine. So you produce more urine? who cares? It's going into a stupid bag - you don't even have to get up to pee.
Life is too short to worry about this stuff. you've just beat death. celebrate.