What Causes Pain In Buttocks Radiating Down The Leg Post Spinal Surgery?

I had surgery in January for a herniated disc pressing on the sciatic nerves. The pain was from my buttocks down my thigh and leg. Other symptoms were tingling, feeling of heat and numbness in my leg. I can't walk or stand for over 5-10 minutes before the pain will start again. It has been 6 weeks and I am having the same pain and symptoms described as above as I did BEFORE the surgery. I am going to therapy 3 times a week but, the symptoms persist. When will the pain go away so that I can have quality of life again. Thank you!