Years ago I did considerable running and races, coupled with heavy weight lifting. I suffered through three stress fractures in those years, and, thankfully, not all at the same time. (One broken leg at a time is enough!)
Your leg is truly broken. Your option is to take six to eight weeks for it to heal, which means no hiking and certainly not doing Mt. Whitney. I recommend giving your spot to a friend or notifying the Forest Service that you are not going to use your permits.
Two years ago I was scheduled for a Mt. Hood climb and managed to badly sprain my ankle days before I was to fly to Portland. My option there was to cancel my flight, which cost me $100. I guess it could have been worse.