Do what you need to do for yourself today (or as soon as you can if it's a travel day).
Eat lightly and blandly if your belly is weary.
Drink just water if your head is aching.
Sleep more if you're tired.
Be alone if you're tired of people.
If you're not, be with just those who give you energy rather than draining it.
Take whatever forms of rest you need. It's good for you to be good to yourself.