You seem to have a prolapsed inter vertebral
disc, rightly at L5S1 region. This disc may be compressing upon a nerve root
that either exits or traverses through that level. Having known this basic anatomy, you must avoid any activity that aggravates the condition, like bending forward and lifting heavy objects, sitting long hours on computer, inappropriate sitting posture, etc.
The medications will relieve pain and help muscles to relax. Physiotherapy
shall also help a lot, especially exercises that strengthen your back. Kindly note that exercises should only be done when it doesn't hurt. Adequate rest and proper nutrition is equally important. Drink lots of fluids since dehydration
affects the disc.