Welcome to HCM,
It seems that present medicine is not working against infection you are having and seems to resistant to penicillin.
It is better to go for throat swab examination for causing organisms and medicine effective against them.
You may go for higher antibiotics like Azithromicin after consulting your doctor.
Do warm water or listerine
Take light diet.
Avoid fried and junk food.
drinks and ice creams.
Ok and bye.