What Causes Pain In Buttocks And Thighs?

hi Dr, Im 38 year old And had no medical condition before. But since the last 3 weeks i had this very severe sharp pain in the right buttock going down the back of my thigh down to below the knee. so my PD prescribed some soma and ibuprofen for pain. i have been taking it daily as prescribed but the pain is still there, it gets worse when i walk very little distance and now i feel that my whole right leg(back) feels numb. what should i do next.