Thank you all for your responses! I got scared last night when the swelling/heat/discoloration seemed to be getting worse and worse, but it's visibly calmed now. I haven't tried to walk farther than the perimeter of my apartment, and the pain's mainly been odd pinches in the side of my foot, where the suffused pain is usually the worst. We'll see if I can get to work tomorrow--four-block walk to the train, and the sidewalks are too icy for crutches. I have no backup plan at this point, so wish me luck!