I am on gabepentin for my sciatic nerve pain. They are trying to calm it down so I can have physio on my back and leg. My leg is suffering greatly , very painful and it is very hard to walk. This is my 4th day on the drug. My second day on full doseage of 300mg 3 times a day totaling. 900 mg I not feeling much relief. Should I be? Or does it take longer ?