Could be due to disc bulge in low back, Manual physiotherapist can push the disc back to its normal place ,try itm GOOD LUCK

Do the cat/cow stretch. Get on all fours, with your arms straight and your hands directly under your shoulders; your knees hip-width apart.

It can be serious if it is hurting you that bad. Consult a physio and an orthopedic doctor. So that you can have an mri or X-ray done and rule out the problem

Don't worry you will be alright soon,Find a good physiotherapist as in your situation medicines usually don't work. Ask for Manual therapy and LLTT technique.Those are famous and effective treatment Same time ask for IFT for back and TENS for affected leg .your pain will subside in 5 to 7 day .Then they may give you mcanzee protocol. 

Sciatica nerve compression, First consult u neurologist, after that go for physiotherapy treatment for few weeks, take proper rest, avoid bending,weight carry.

X-ray must. Start physiotherapy immediately

Have hot fomentation. Avoid prolonged sitting & standing  periods. Avoid weight lifting & forward bending. Consult an Orthopaedic Physiotherapist, he/ she may assess you completely than decide your future treatment plan They may advise you about ergonomics They may reach you spinal & core strengthening exercises