I Have A White, VERY Painful Sore At That Back

I have a white, VERY painful sore at that back of my throat, that is surrounded by redness. Lymph nodes are tender, painful swallowing and hoarseness. Webmd showed possible condition: Peritonsillar Abscess. States that it is an “urgent condition” & said contact doctor or 911. To me it looks like a painful but simple canker sore that you would see on the inside of your lip, but this is center back of throat. Please advise.