A bug is one thing. A virus is another. It doesn't just leave. You may just need to go on antibiotics for a week or so.
I'm saying all this because I think I got what you are talking about, without the throat itch. I suddenly feel run down for periods of time over the last couple days and I'm positive it's not the flu. Also have a small mouth sore. I've been here before but usually it involves my throat. If I'm dragging tomorrow, I'm making an appointment for Monday. All the Doc will probably due is take a culture from inside the mouth. He'll know if it's something antibiotics will clear up. Not only do I hate being sick, but I got a little biz to run. And things don't stop cuz I do.
BOL