I make a ginger infusion (grate fresh ginger and add boiling water. Put in a thermos flask and use/dilute when needed) to which I add lemon and a dash of honey.
The ginger clears my nose.
The honey is an anticeptive
The lemon does something else which I forget.
If I need anything more, I down it with some paracetamol.
Bear in mind if you are feeling under the weather with diabetes, your BG is likely to rise so monitor closely.