I don't recall an recent injuries just prior to symptoms. Haven't even really been noticeably sick in the past year that I can recall. My white blood cell count was 4.2 the first time I saw my GP (a week after symptoms started)

I do have a small painful cyst like bump on the sole of my foot (podiatrist didn't even know for sure what is was) I thought maybe it could be the sign of something viral, but white blood cell count was on the low side of normal.

Thanks all for the leads. I'll browse the links and see if anything clicks. I'm really stumped at this point, but plan to keep investigating.