I have one inflamed tonsil but the white pus is on the tonsil, roof of my mouth and under my tongue. what is it?

Probably: Probably infection, fungal, viral, or bacterial. Anything red or white in the mouth should be investigated. See your physician or Dentist to start the diagnostic process.

Strep throat: is a bacterial infection that causes inflammation and pain in the throat. See your doctor for evaluation and a rapid strep test in the office. Good luck.