Hi. Lower back pain which is travelling to the legs could be due to problems in the lumbar spine disc called disc bulge or disc prolapse. There is a good chance that you're symptoms are self limiting. If the pain is severe, we should consider get a lumbar spine x-ray - AP & lateral views and consult with a pain physician or orthopedician. Till then, don't aggravate it further. Good luck.
Next Steps
Basic painkillers like Tab Paracetamol 500 mg x 3 times a day, after food.
X-ray - Lumbar Spine - AP & Lat views
Health Tips
Avoid lifting heavy weights, jerky long travels.
A firm bed mattress will help.