Cold/flu symptoms for about a week, sinus pressure, congestion, cough, perhaps mild fever at some points (didn't measure). I thought I had rounded the corner two days ago when noticing overall improvements but yesterday and today I have a white blister-looking thing on my right tonsil accompanied by quite a bit of pain when swallowing/coughing. The pain is definitely on the right side around what looks like a blister, the other side of my throat is in no pain. I also still have mild versions of the aforementioned cold symptoms.
I plan to go to urgent care tomorrow.

Cyst? Infection? Can I anticipate a round of antibiotics or is this more serious?

Thank you