My upper body underneath my ribs hurt whenever i breathe and some of my upper back is slightly uncomfortable, what could be wrong?

Probably muscle pain: Although the most likely cause of this is musculoskeletal sprain/strain, a few simple tests can rule out anything more serious. If there is a significant history of injury, rib x-rays should be done to rule out a fracture. A 2 view chest x-ray should be done in any case to rule out any underlying lung disease, such as pneumonia, especially if you have shortness of breath.