I decided to go to the doctor about 5 minutes after posting.
It took me about that long to realize that if I was concerned enough to post on Bhuz, it was probably in my best interest to go. I do have health insurance, so it only cost me a $15 copay.
They did x-rays to be sure, and have confirmed nothing is broken or dislocated. The doctor says it's hard to tell right away, but he suspects it's only bruised based on my range of motion and level of discomfort. He suggested icing for 20 minutes at a time, ibuprofin for the pain/swelling, and taking it easy. As far as the workshops and show, he told me to just listen to my body, and let it tell me if I'll be up to either or both.
Thanks so much, everyone. I plan to take the stairs a little more slowly from now on.