Good news! I went to the chiropractor and he thinks I have a strain and possibly a small tear in my tendon. He says it's unlikely to be a fracture, given that I can walk and his tuning fork didn't show any bone problems. He did give me a form for an x-ray if I want one, but I don't think I'll bother. He adjusted it and told me to ice it and use Traumeel on it. He thinks it'll be better in a few days... I think that's overly optimistic, but I hope he's right!
Good. I too could walk second day, but it took 4 months before I could do anything vigorous.
One thing that definitely helps (from my experience) is to take a course of glucosamin/chondroitin tablets. These are the building blocks for new tendons, and it is thought that it helps promote re-growth. Link. It helped me.