This seems to be nerve
compression causing constant pain and loss of sensation,commonly called as sciatic pain. Now it is a mechanical problem which can be helped only by multitherapy.please consult a neurophysician first,For relief of severe pain
he will prescribe an antiinflammatory drug acc to your need,you will have to take it untill you are comfortable with pain, do hot fomentation atleast twice daily at painful site and nearby area ,simultaneously u will be advised for rest if u are working, please take leave for some weeks, as rest is very essential,avoid leaning down,indian toilet, lifting heavy weight, any kind of jerks etc,your physician may advice u for shortwave diathermy, please follow his instructions sincerely.
All this treatment will gradually give you symptomatic relief and will reduce the compression over nerves, so hopefully you will be better in some weeks time. If this treatment does not reduce the symptoms then you might have to take the openion of a neurosurgeon, but surgery is only advised in a worst condition only, hopefully you dont belong to that catagory of patients.