Could just be the alcohol, which is a diuretic.
Most people do seem to eat carbohydrate as though it was an essential part of their diet, which we are encouraged to think of it as, and many would feel a lot better, and be a lot thinner too if they cut back. I tried to eat low carb for decades before diagnosis but was always told how dangerous it was. Yeah - right.
Hopefully you will be able to get a test done quickly and get the results some receptionists guard test results like a dragon on gold. Maybe ask for a telephone consultation with the doctor, or for your results to be notified if they will do that at your surgery.