Thanks for replies

How very encouraging - thank you both very much. I shall carry on as though nothing happened (plum? what plum?) and ignore the brick I now feel in my stomach!
I think what clinched the (temporary) failure was the thought that I have to help at my local animal sanctuary tonight and babysit for an ADHD-affected child tomorrow night - both of which require energy and neither of which can be done with a severe headache!
I shall visit here often for encouragement and reassurance - it's hard to do this on your own because you don't know what all the feelings mean, and I've had so many people tell me that fasting without supervision is dangerous (I know this isn't fasting as such, but it's the nearest thing I've ever done).
Anyway - good to know that I can have peppermint tea - I've been drinking hot water in the morning because I miss my rooibosch, but I love peppermint so I shall have that from now on.
Thanks again!
Cathy