I became sick last mon. w/ nausea, sore-throat and fatigue. it went away, but my throat still hurts only on the left side by my tonsil. getting worse.

Sore Throat (ST): Most sts are caused by viruses especially if associated with a cough. Strep is a common bacteria that causes st - often treated with antibiotics (abx). Most all of these will run their course and cause no issues. There is something called a peritonsillar abscess where an abscess forms and causes difficulty swallowing, trouble breathing, and difficulty opening mouth. This needs drained and abx.