Just curious as to how the diagnosis of 'stress fracture' was made. Did you have Xrays or a CT scan? Who confirmed the presence of a fracture, the emerg doc (who often misinterpret radiological findings) or a bone specialist (orthopedic surgeon)? What bony element of the shoulder suffered the stress fracture, the humeral head or part of the scapula?
If you do indeed have a fracture, you're likely not going to be able to train without significant pain for at least 6 weeks. Bony injuries do not heal overnight.