That's more or less a how long is a piece of string question. We have no idea because we're not you, it could be days, weeks, months, the thing is if you are worried go see your Dr again.
Diabetes is not the only possible reason for your symptom, especially for fellas of a certain age.
It's actually not an easy question to answer because the answer is a bit "it depends" - I had a fair number of symptoms, none pleasant. The one I didn't have was frequent urination - I had severe water retention instead. The good news is that all symptoms either went away completely or reduced to next to nothing very quickly once my blood sugar came down to normal.
However, once I was back in normal range a couple of symptoms arrived that I'd not had while my BG was high - the main one was xerostomia - the dry sticky mouth thing.
I think I have some permanent damage to nerves in my feet from neuropathy, and a little bit of residual oedema every so often. The thing is that high blood glucose over time does physical damage. Controlling the blood glucose prevents further damage, but doesn't repair damage already done.