My throat has been feeling "itchy" lately. I thought I was coming down with a cold so I began taking some echinacea. It's been several days and the scatchy weird feeling at the back of my throat has only gotten worse.

I looked in a mirror with a flashlight today and found a white spot about half a centimeter long where my left tonsil is. Is this a cankor sore? Should I be concerned? When I swallow, there is some pain.

I also have a slight cough.

Has anyone every experienced this before? (Finding a cankor sore(?) where the tonsils are?)