Hugging someone, or a pet, or a pillow. Maybe even falling asleep like that.
I was so tired after hospital yesterday that as soon as I got home I collapsed in bed and just hugged my pillow. It was so damn fluffy and soft and comfortable. Totally fell asleep for 15 min after that… Anyway, hugging releases oxytocin and endorphins and a whole shitload of feel-good hormones, so you should go hug someone. Right now.