So what did I do?
I ate four squares of dark chocolate.
Y'know what, a couple of minutes after that I was feeling absolutely fine. Chocolate is indeed the stuff of miracles. I took choir practice with a smile on my face and, even though I flaked out at nine o'clock and went to sleep, the little of the evening I saw was lovely. I think I must add chocolate to my emergency supply of medication I have in my bag. It shall now be Germaline, Bonjella, soluable aspirin and chocolate.