Suggest Treatment For Sinus Infection

Question: Hello...I have a question regarding what has become a very painful condition with my tongue. The appearance is an open sore about the diameter of a pencil eraser. It is surrounded by white discoloring and is located on the underside near the rear of my throat.

At first (3 days ago) I was experiencing what seemed to be the onset of a sinus infection...sore throats that radiated up into my ear. However, over the next 24 hours, the pain began to seem more localized to the tongue...in an attempt to play Dr. I grabbed my IPad and took a few attempts at catching evidence of a red throat. What I captured was the above description. While the initial cause remains a mystery, I am fairly confident, a damaged crown on a back tooth is coming into contact throughout the day...I am an educator and quite literally lecture non stop for 6-8 hrs.

I have an appointment to have my tooth repaired in a week but if the past two days represent an ongoing increase in pain, I will be unable to eat, drink. My question's.

1. Am I am overlooking additional, more critical possibilities? I.E. a viral infection etc
2. I have avoided a prompt care visit because I don't believe they could do or prescribe anything I cannot get over the counter...is that true? I am currently treating it with a mild numbing oral gel used for tooth aches or gum issues..I also have been coating the suspected tooth area with wax used by folks who have braces. I tried a more potent liquid numbing agent and WOW did it hurt.

I wish I could attach a photo for visual consideration, which I have but it appears this site does not provide that option...any thoughts advice or words of wisdom would be welcome.

Kindest Regards XXXXXXX