Your doctor has put you on the correct medication...if your symptoms have still not improved I would suggest you to take T.Roxithromycin 150 mg bid for three days and continue betadine mouth gargle...avoid oily and spicy and cold food...drink only warm water....if still symptoms persist then get a throat swab done as your doctor suggested.
Health Tips
Tips- drink warm water,gargle with warm water with salt added twice a day,drink jeera water frequently(add jeera to water...boil it and strain it... drink this water frequently)