Running under circumstances of inadequate recovery can produce stress fractures and cartilage dame, so this is not entirely surprising. It is also not very surprising that a doctor would immobilize such an injury, since they don't seem to receive any training in the mechanism by which these things heal. Use the search function to familiarize yourself with our approach to injuries, and then decide what to do. It is your knee and your career, not ours and certainly not the doctors.