Hi Lisa! My sister had that same problem for years, got to the point where she could barely use her left arm, couldn't raise it above shoulder level. And very painful. After going to dr. after dr. she finally had an MRI done. Turns out it was something with her cervical discs pressing on a nerve relentlessly. She is now recovering from a surgery that replaced the offending disc. My advice to you; get an MRI! It would be awful for you to go through all that pain for so long without any answers.
Hope all goes well for you!
Hey Lisa!
Well, without a clinical evaluation it would be difficult to determine the cause of your symptoms. Shoulder pain could be caused due to infections, inflammations, degenerations, capsulitis, bursitis, tendonitis, injuries/ tears, arthritis, spinal/ neuro-muscular causes, muscle/ ligament/ tendon tears/ injuries, fractures, growths/ masses, ischemia, micronutrient deficiencies, referred pain from other regions etc. I would suggest getting the symptoms evaluated by a primary care physician initially and depending on the cause diagnosed/ suspected, it can be managed accordingly or specialist care may be sought.
Hope this is helpful.
Take care!