Hello there, I am dr.milan an infectious disease specialist answering your question. You need to go for culture & sensitivity test by a reliable Microbiology lab and by a qualified doctor Microbiologist. We need to know which type of infection is there. Staphylococcal, fungal and many bacterial sore throat ma have same clinical picture so once you do culture than we will manage according. And if you are allergic to that much drugs don t worry there are many drugs available in market. It can be manageable. But just take car you infirm your treating physician every time about this drug allergy Hope i have given appropriate guidance to you. if you have any query you can consult me anytime. Give me star rating, helpful vote & thank you according to your satisfaction level. Thanking you.