My first thought is get her ears checked because whenever DS flips like that, he usually has a double ear infection that nobody knew about. It's happened to us at least 5 times!
Other than that, I'd say put the principal off until after the holidays. Our kids are so sensitive to changes in schedule, people coming to visit or not, stress in the air, the weather changing! I don't think making any decisions in Nov/Dec is ever good for anyone!
Sounds like you have a bit of a perfectionist. I have one of those and I am one too... I wish I had great advice for how to stave it off quickly but I don't. I just try to talk to DS a lot about mistakes and learning from them and talk about famous mistakes all the time. Sometimes I mess something up on purpose (like burning toast) just to say "Oh well" and start over.
