Sounds like inflammation of the femoral nerve (like sciatica only a different low back condition). However, are you sure you don't have an inguinal hernia on your left?
The general treatment of low back pain is: maintain a normal weight, do stretching, have good abdominal musculature (this means exercises involving sit-ups), use of occasional ibuprofen or naprosyn, ice to low back. Be careful how you move and lift.

