Hi welcome to the health care magic Your posterior pharynx examination should be done by otorhinolaryngologist or nearby doctor... Your throat swab simply can be taken and sent for culture according to which specific antibiotic prescribed.... Drink hot water and do three times per day salt water gargling Avoid excess spicy foods and fatty meals for few days Take decongestant like chlorpheniramine for congestion relief Hence without getting panic consult doctor for examination and accordingly get your prescription Hope your concern solved