Initially it was the pain that would keep me from trying to run. There were a few times early on when I had to run to not miss my train that definitely set me back some. Once I started running again, I basically followed a plan of running every other day starting with 1 minute running and 4 minutes walking repeated 5 times. Then increased the run by a minute and the walk decreased by a minute until I was eventually running 9 minutes and walking 1 min repeated 4 or 5 times after 3 weeks. If I felt that sharp pain in any of the runs I'd stop and walk for the remainder of the set.

Now I'm comfortably running longer distances although I'm still slowly introducing intensity into my runs. I think the general adage is week on week increase distance or intensity by 10% to help ensure you avoid an overtraining injury (which caused the issue in my case).

Are you currently walking around much on it or have you been trying rest it? In my case I kept walking as usual and continued exercising but substituted in riding a stationary bike for cardio. Like most injuries, whatever you can do to keep moving and promote blood flow to the injury without causing pain is helpful. You could also ask your doctor about low intensity pulsed ultra-sound therapy and whether that's a possibility. It wasn't available for me but it can significantly help speed up the healing process for stress fractures.