What Is The Cause And Treatment For Lower Back Pain?

My back pain covers my entire back from one rib cage to the other. The pain is concentrated about in the center of my back and is present always. If I do any form of minor work like walking to the mail box or lifting cups and plates at home my back pain increases signifinctly to the point I have to lay down for a half hour or more. What worries me more that I have a severe lose of all my body streanth and breathing is very labored. I moved 3 years ago and lifted a lot of heavy boxes. At the time I noticed this and it has gotten worse. I am currently undergoing cimo for pancreatic cancer.