sesamoid sufferer
Likewise, I have dealt with senamoiditis, which is a semi-rare occurrence in runners, but potentially career ending. You end up with a stress fx of the sesamoid, and you are pretty much done as a runner.
However, mine has really only taken a few days or weeks here or there of management. Get some dancers pads and throw them in your running shoe on the affected foot. I was able to cut mileage and run through it without any pain doing that while it healed. But yes, I agree on the stiff-soled soles (Birkenstocks with sesamoid pads in them were great). I found walking actually more painful than running because of the heel-toe motion of walking. I'm a mid foot striker when I run, so that was less painful.
My doc, however, strongly recommended against cortisone - you risk weakening that bone, and it's a high risk area for a fracture. Fractured sesamoids easily lead to necrosis and potential removal, and then you DEFINITELY aren't running again.