Yeah, I've been like that my whole life, lol. Especially when I was a kid. If I got a cut, I thought for sure I was going to have blood poisoning, lol. I've been Googling more earlier today, just trying to find some peace of mind. Apparently, it can be caused by inflamed sinuses. Mine have always been horrible (I just hit the genetic jackpot, didn't I?) and they've been messed up on and off for about a month or so, now. I'm still going to try to get a doctor's appointment soon, but I just needed something to calm me down, y'know?
I hope your thyroid gets better.