a few things i would like to know, do u have difficulty in swallowing also, and did u take antifungal agents also.
see i think it is a fungal infection
of throat probably candidiasis
. it usually occurs when our immunity goes down, or a person is on antibiotics for a long time that kills the normal commensal bacteria of throat. so it is advisable that u to go to a throat specialist who will examine, do needful tests and start some antifungal drugs.