You have developed a folliculitis
which is an infection of the hair follicle.
See a dermatologist
is the best person to consult for any such infection of the skin.
You have been advised a course of oral antibiotic drug which I would say is very essential in your case and should be completely taken in the dosage as advised.
In addition, make sure that you keep the affected area clean and dry.
Apply a topical antibiotic
cream over it twice a day.
Dr Geetika Paul