You are having a problem called Sciatica. In modern medicine the treatment consists of pain killers , traction and ultimately surgery. I am an allopathy specialist , so believe me when I say this is not the route you should follow . Better and safer treatment is acupuncture at the hands of a qualified Doctor. Along with that you can also take Ayurvedic panchakarma therapy.

That's a classic case of entrapment neuropathy occurring at lumbar spine often better known as sciatica. Do not lift heavy weights or bend down. Maintain good spine posture. For drugs, please consult a RHeumatology or neurology