Why do my tonsils hurt when I get the white stuff on them?

Ok, so I got this white stuff on my right tonsile and it really hurts to swallow or even just talk. I get it sometimes ( every once a year, i already got it in the winter and it wasnt bad, i just took some A-Bs) now I can praciticly move my right tonsil up and down! am I over reacting? please help.