You have not mentioned the duration of the problem that you are having, but if the back pain
has progressed to buttock and thigh pain and then to numbness
in the right foot, it is highly likely that you have a nerve root compression
in your lower back, most likely due to a disc prolapse
. You must undergo an MRI to identify and confirm the level and reason of the compression.
The medication should give you pain relief briefley but if the numbness and weakness in the foot and leg are increasing with time, it is wise to get an evaluation done by an orthopedic surgeon or spine surgeon
as early as possible to prevent further progression of the neurolgical deficit.
Good luck and get well soon.