It seams your neck muscles restricting blood flow, that may be cause of your vertigo.
Shoulder muscle is a complex one, it need to be evaluated by the properly.
Next Steps
Visit nearby physiotherapy clinic for further assessment and management.
Health Tips
Avoid overhead activities.
Try hot pack over your neck area.
Avoid pillow, use towel rolls that support your neck but make sure your head should touch the bed. So adjust the height of the towel roll accordingly.