What Causes Left Sided Pain In Neck And Shoulder Post A Bout Of Asthma?

I spent the first ten days of this year in hospital with an acute asthma attack (totally new to me, never had it before). Since then, I have had pain in my left neck, shoulder (not the joint) and upper arm (tricep, not bicep). I cannot put my arm out to the side and back without terrible pain in my tricep. My doctor called it frozen shoulder but it doesn t fit the description of it. I use Dr. Ho pain therapy daily, ibuprofen and stretching exercises, which help somewhat but I would like to fix it if I can. I suspect sleeping for 10 days on bad pillows has perhaps pinched something somewhere.