Pain In Upper Back, Increases With Deep Breathing. Sore Muscles, Headaches. MRI Shows Tendinopathy. Related Symptoms?

Hello. I am a 24 year old female with pain in my upper back, underneath the right shoulder blade. The pain increases with deep breathing. I ve had this pain for several months after a car accident. The pain used to be a deep, throbbing sensation in my right upper arm and now the pain has moved to the scapula region. In addition, my muscles always feel tender/sore in that region. Even my headaches usually start at the base of my skull on the right side and the pain radiates up to my temples. I ve had physical therapy treatment and it didn t feel like it was helping or reducing my symptoms. I also had an MRI of my right shoulder and the results were supraspinatus shoulder tendinopathy , bicipital tenosynovitis and question of superior, posterior quadrant labral tear. Are these symptoms related? What could this be? Thank you for the help in advance.