I think you're forgetting you've just had major surgery. It's TOTALLY normal to be exhausted after very little activity. Many don't leave the couch during the first week. You're 7 days post-op, for gosh sake! Comeon, girl! Give yourself a break!
It's great that you're enjoying a social life, and as long as you can handle it, go for it! Just don't worry if you're exhausted after a foray out of the house. Give yourself a break, though, and be careful not to overdo it. After a fun social event, give yourself permission to flop down on the couch for a rest.
Also, don't forget that your wrap is swelling as we speak. Don't be surprised if you get some discomfort and more difficulty swallowing at about the 2 week mark.