I think it would be a good idea to schedule an appointment with a new orthopedist for a second opinion. Your other option is to go to a neurologist. You need a diagnosis before you can get effective treatment. Your left shoulder is most likely acting up because you are over using it in order to protect your right one. This will continue to get worse if you keep working. You might want to decide if you can afford to quit working until you get a diagnosis and effective treatment.