Dang sorry to hear that boo, I'm hard headed, I took a week off and went back to training, now everynight at the 2.5 mile mark or there close to it I can feel my foot twinging.
I would say don't switch your entry just yet, whens the race? I would wait till the very last point where you cant get a refund and then decide.
You might feel way better by race day,or at least I hope you do!