yes you must consult your doctor again as the infection is not controlled by penicillin .
but it will be wrong to change the antibiotic without examining .so i advice you to consult your doctor.
Now what u can do is start Betadine
gargles 2 tsf in half glass of water for gargle 3 times a day.
And also U can do gargle with Voveron gargles 2 tsf for gargle 3 times a day and spit it.