Hi
To understand it in simple terms, when a person is in a state of chronic stress. It has its impact on the human body as well. The stress gets accumulated in certain areas/ parts of the body. Which keeps our body in the state of distress even more. Pain at the shoulders, neck and back are most common body parts where most people feel it. Along with pain, you may feel a certain kind of tightness/ stiffness etc.
Next Steps
Had just one session with a psychotherapist? carry on with more. she would teach you some exercises which helps in psychosomatic pain.
Also, work through your concerns related to the workplace. If that is the cause ?
Health Tips
Choose the right psychotherapist for yourself ( RCI LICENSED clinical psychologist). if yours is the one, trust her and give it some time.
Try doing basic movements of those body parts to keep them relaxed- body scan exercises can help.
work through your issues of office.