IF, and it's a very big IF, you were to have undiagnosed diabetes, you would be suffering from high blood sugar, not low. you say you find that your sugar levels have dropped during the night - how do you know this? it's more likely that you've got into the habit of having something to eat when you wake up during the night. the weeing is really neither here nor there, lots of people get up 2 or more times to pee during the night, and it too can become a habit.
as has been said, it's very easy for the practice nurse at your surgery to do a dip stick test on your urine to give some indication as you whether or not it needs more investigation.