So, after my big week of running last week, I thought that I had escaped without being harmed.
I have discovered that the pain in my foot is most likely extensor tendonitis, instead of a stress fracture. This means that it is reasonably "safe" to keep on training regardless, although it may start to hurt like a mean mofo. Icing the affected area seems to abate the pain, and it is never as bad after running as it is before.
Nevertheless, I feel a fair amount of fear and uncertainty about my near-future of running, with questions like: will it actually heal by itself? What if I break down? What if it causes other problems?
The last question has been partially answered - my left inner-quad feels very twingey, and the place where it connects to my hip seems to pinch when I lift my leg too high. However, provided that I continue to take it easy this week, it SHOULD sort itself out (having now said that, it probably wont).
In any case, I had five good weeks of running, and was bound to have a bad one pop up at some time, so I am not bitter about it. I am still enjoying just getting out there everyday.