Go to a chiropractor - they should suggest that you get an x-ray done (ask for one if they don't). This will give him a direct view of your spine to see if your spine is in the correct position (I'm willing to bet it is not). Many people with lower back pain have what is known as 'subluxation of the spinal cord'. Some subluxations occur from accidents or specific injuries however many develop through our regular lifestyle. Poor posture, improper lifting, long periods of sitting, stress and chemical imbalances (drug, alcohol, toxins etc) can all lead to subluxations. A study was done by a German doctor who tested 1000 newborn babies to see the positions of their spines after the birthing process. What he found was that 47% had moderate to severe subluxations.
Improper spinal function can rub, choke, 'pinch' or irritate the delicate spinal nerves. You may feel pain, tingling, numbness or a pins and needles effect. The messages your nerves are sending may be altered or blocked causing dysfunction in other body parts.
With spinal joint malfunction the discs, ligaments and other connective tissue are also affected. the soft, pulpy discs that separate each spinal vertebrate can tear, bulge, herniate or degenerate. Inflammation and swelling accompany the accumulation of blood and lymph, causing a rise in temp. You may develop swelling or tenderness (this may account for the discomfort you are feeling in your lower back area).
No matter what anyone tells you on here, no one BUT a doctor can properly diagnose your condition. If you do (and I suggest that you do) see a chiropractor, be sure that x-rays are taken. Any chiropractor can simply start doing adjustments, but without a clear understanding (which cannot be properly determined without x-rays) the problem will only persist.
Good luck