Is 2 years old the bi - polar years?

So we're living in Virginia now for a while, and things have been good. We've visited a lot of really great places, and seen wonderful things. Problem is, Syd has also decided this should coincide with her "terrible twos." Now, I've heard of this before, people say then it becomes "terrible threes" etc., but seriously. I. had. no. idea. It isn't just terrible, it's catastrophic, it's like she's become a whole new entity, capable of breaking the sound barrier with a scream, possibly making my whole head, not just a few hairs, gray and giving me 10 years or so worth of lines.
Today, after doing the supernanny thing, and putting her to bed the 34th time while she scream/laugh/cries at the top of her lungs, and trying to watch Lost, which we now have to watch on the computer later, she decided to throw herself against the window ledge away from my reaching arms. Well, you can guess what happened. She cut her lip, or the area between her lip and nose, a nice straight split right in the middle. Don't know if she'll need stiches, we're icing and giving meds and seeing in the morning, but I'm sure I'll worry about it unless I do go in, so there it is.
Tell me, even if it becomes the terrible threes, it will not be this! I love my baby girl, she's fun and lively, but boy, she crazy! (right now)
I'm sorry that my only recent post happens to be one like this and not all the fun things we've been doing, and I promise to get to those again real soon. But I think just writing it down now, makes it a little cathartic. Well, we'll see tomorrow when she kicks and screams because she wants to watch "spongybob."
An angel, lovey and nice one minute . . . . poor baby, maybe life's just hard at two for them to . . .