Chronic upper back pain. To that?

27f .chronic upper back pain since 1 and half year.used all types of pain killers multivitamin etc no cure.it's less when iam laying and more when I sit and do work .Also on and off low grade fever with giddiness and weakness (not continous but on and off). The pain is more just below the neck and middle upper back .in the early morning when I try to stretch my upper back forward I feel pain.while forcefully breathing out I can feel pain.MRI is normal .all blood tests normal what may be the reason plz help . This all started when I took steam inhalation directly from stove on high flames daily for 45 days thrice .after this the pain and throat irritation started throat irritation cured after 6 months but this upper back pain isn't curing.Also in 2020 hrct it showed bilateral minimal plueral effusion and infective etiology.is this pain anything related to that?lungs Plz reply.