I think it's important to remember the last few days have been pretty full on for you anchorbird - I'd be surprised if you weren't rocked back on your heels a little bit...
there are some good suggestions here tho - exercise is good, gratitude lists are good, journalling, doing something good for yourself, doing something good for others
if you feel concerned tho, obviously the Dr will be your best bet.
Hope the funk lifts soon
D