Ouch! You should not need to be i that pain.
I am 5'4 (I realize we are all shaped differently), with that said, I am on a 50cm bike. Did they have you try a larger frame bike? I have a long torso, so the handlebars were not an issue. I did not "fit" on a WSD, probably due to my liong torso and shorter legs. I fit very comfortably on a 50cm to a 51cm frame. Anythingn smaller and I felt very uncomfortable-my not so local bike store is located at a trail head, so they let you ride as long as you want. It truly helped me find the right fit.
I noticed others mentioned shoulder exercises. I carry all stress in my shoulders and neck. Luckily or wit a good fit, my bike has not caused any shoulder pain.
Try being off it for awhile. Ride some larger frames, and if the pain is persistant, please see a doctor.
Jennifer
“Live as if you were to die tomorrow. Learn as if you were to live forever.”
-Mahatma Gandhi
"We are what we repeatedly do. Excellence, therefore, is not an act but a habit."
-Aristotle