Morning Bob, sorry I dont have an answer for you but I just googled it and from what I have read, I would go back to your doctor. Although he gave you tablets for you nose there are many other causes eg, liver/kidney problems, throat infections etc. He will need to address all of these possible causes and eliminate them. Since you have been to your dentist and your teeth are ok then you can be pretty sure its not that.
10 years is a long time to suffer this and I am sure you are totally fed up, have you looked at the types of foods you eat? Smoking and eating garlic will not help the situation.
I do sympathise with you as mrwarpig suffered this for a while and it really did get him down, turns out a few trips to the dentist sorted him out. But go back to your doctor and keep going until its sorted for you own peace of mind.
good luck
warpig