Over the last few hours the roof of my mouth has been sore, as if I'd burned it, but i know I didn't. i just shined a flashlight in there, and was surprised to see the entire back of my throat a strange yellowish color changing to red at bottom, and a brighter red spot on the roof of my mouth. My tongue is mostly coated with mostly white, but not all over. I've been struggling with digestive issues and tenderness in my lower abdomen for the last 4 days, some fatigue, and now this. Any advice?