Thanks for the query to H.C.M. Forum.
Without physical examination it is very hard to say whether it is tonsilitis
or quincys (peritonsillar abscess
Anyway the main cause of this is bacteria.
In my opinion levofloxacin
500 mg / day for five day is the best drug.
Antiseptic solution gargles will provide local relief, ( HOT SALINE ALSO).
As far breathing problems , it may be due to allergy ( if sneezing
, tears in eyes, mucus from nose present).
If allergy consult a physician and get treatment.