Thanks everyone for your well wishes.
db and I went to the hospital Saturday afternoon because all of the clinics around here close early on Saturdays, but it turned out to be for the best. While I was there I had a chest x-ray that revealed I had pneumonia. I know it's not good to hear a doctor tell you that, but I was actually relieved because at least I knew what I had, and could be treated for it.
So I'm on antibiotics for a week and they do seem to be helping as each day I have a little more energy, and am coughing less. One downside is that a side effect of the drug is headaches, and I'm getting one daily at around the same time that stays with me until I fall asleep at night. Not fun, but at least I'm getting better.
I hope to post more vacation pictures soon.