There will be time enough for flitting around like a social butterfly later. Right now, your energy is much more suited to introspection. You don't necessarily need to spend the day by yourself, but it would definitely be in your best interests to keep things low-key and mellow. Despite what others may tell you, being in the middle of raucous activity is not the best for what ails you. Tell those people to go off and have fun without you. You've got a date with a couch.