I'm sorry that your interview didn't go well.

Here are some of my ideas:
Get a pedicure! I got my first one recently and now I'm addicted. Every time I look at my perfectly polished toes, I feel happy. My pedicure has lasted almost three weeks. And it's sandal weather, perfect for showing off those toes.
I also like the movie idea; this would definitely be at the top of my list. If you can't go to a movie because of your son, rent one. Heck rent a couple and watch one tomorrow to.
Call (or do something with) a friend that can commiserate (or who will take your mind off it).
Have your favorite meal that fits into your diet for dinner.
Pamper yourself. Stop at the drugstore and buy some luxurious bath products and some light reading (maybe some fashion mags), light some scented candles in the bathroom, and take a long bath.
I might also send an email to the person who interviewed me, thanking them for the interview (it's a good idea to do this after any interview) and addressing the issue. I'd say something like, "During our interview, I got the feeling that you are concerned that I am too extroverted for this position. I want you to know that I appreciate your concern and I wanted to take a moment to tell you why I think that, despite this, I am a good fit for the position..." Then talk about how you'll adjust your extroverted behavior to fit the position, AND/OR how you think your extroversion will actually benefit you in the position, AND/OR how you plan to deal with the fact that the position might not fulfull your needs as an extroverted person (and maybe how it will fulfill other needs that you have).
Also, I know that when I have interviewed people, I have sometimes talked with them about the challenges that I think they'll have to deal with or even why the job might be difficult for them. It doesn't necessarily mean that I'm not considering them for the job however. In fact, it means the opposite: I don't need to have this conversation with people I'm not considering hiring. I'm just putting that info out there so that if it is a problem for them, they are aware of it and can choose not to take the job. I want to make sure they've considered some of the unpleasant parts of the job and are prepared for them. The last thing I want is to hire someone, have the job be something other than what they thought, and then have them quit right away. I would especially do this if I were interviewing someone that I had a personal relationship with (such as a mentor-type relationship), because I wouldn't want jeopardize our relationship by having them later feel like I had mislead them about the job. It's possible that your mentor was just doing the same thing.
- Barbara