One possibilty for why you have a sore throat: olive oil can cause a burning sensation in the throat if it is high in oleocanthals.
"Inspired by a tasting experience at a molecular gastronomy meeting in Sicily, where he noticed that high quality olive oil produced a throat-stinging sensation similar to that caused by ibuprofen, Beauchamp and his team analyzed freshly pressed extra-virgin olive oil and discovered a compound that suppresses the prostaglandin system, the same pain pathway as non-steroidal anti-inflammatory agents, such as ibuprofen.
Although its chemical structure is quite different from the anti-inflammatory compounds in non-steroidal drugs, olive oil's anti-inflammatory component, which Beauchamp named "oleocanthal," has a similar effect.
Scientists believe this finding is significant because inflammation plays a key role in a variety of chronic diseases."Some of the health-related effects of the Mediterranean diet may be due to the activity of oleocanthal from premium olive oils," said Beauchamp."
The higher the oleocanthal content in olive oil, the more throat stinging it can cause. This is a good quality, because of the anti-inflammatory properties.
If you google "olive oil sore throat", you will find many references where olive oil is used as an ingredient in home-made sore throat remedies.
Your sore throat may very well be caused by something else, but I wanted you to e aware of this property of olive oil.
I hope your throat is better soon.