Based on your answers, some of the most likely causes of your back pain include
muscle strain or spasm
degenerative joint disease (or osteoarthritis)
ankylosing spondylitis (or a related condition).
To decrease pain, rest the back and avoid overuse. Over-the-counter pain medications, a heating pad, and topical treatments (such as Icy Hot, Ben Gay or ice) may help.
While these measures may help, it is important that you see a physician if symptoms are getting worse or not improving over time.