The pain is in the right side of the lower back?

Need to evaluate: Back pain could be due to disc, facet, scar-iliac, muscle strain, pinched nerve, but cannot exclude kidney infection or stone. So, in essence this problem needs to be assessed by a doctor. You might be a candidate for physical therapy which, in turn, might profoundly reverse all of this, but uncover causation first.

Radiculopathy: The most likely cause of your symptoms is a bulging or herniated intervertebral disc in the lower lumbar spine. An MRI should be diagnostic. Most of these cases resolve by 6 weeks. If you're experiencing severe symptoms or difficulty sleeping, see a neurologist or neurosurgeon for evaluation & treatment options. In the meantime try anti-inflammatory medication like ibuprofen or naproxen.