Alright, it's been a weekend and the pain in my foot has died down to manageable levels (e.g. I can walk on it without limping too much). I went to see a specialist this morning; the doctor did some poking and prodding. She took some X-rays which proved to be inconclusive, and ordered an MRI which I hope to schedule for this afternoon or tomorrow. I'm headed back to the podiatrist to review the results of the MRI a week from today.
According to the doctor, there are a few possible situations. Optimistically, it's just some severe tendonitis around and underneath an accessory bone (navicular) on my right foot. Less optimistically, that same tendon could be torn and/or pulling away from the bone itself. Pessimistically, it's a stress fracture.
Swimming and cycling don't hurt much, if at all, so I've been keeping up with those disciplines and will continue to do so until I get a concrete diagnosis and/or someone straps me to the sofa and says, "STOP!"
Ten weeks 'til the race. I'll keep y'all posted.