If a blur of social obligations has left you exhausted, then get some well-deserved alone time today. Treat yourself to a quiet dinner, or rent your favorite movie and just chill out on the couch. It's not selfish to want to be by yourself: it's actually quite healthy. You need downtime to recharge. So when you do get back in a social frame of mind, you'll be charming and fun to be around. Super-social friends may not understand this inward phase you're going through, but they will accept it.