Neurontin and prednisone

I have been taking Neurontin for 2 months. I didn't think it was really helping because I still couldn't function normally. I have had 3 disk surgeries on L4/5, and still have severe pain in my right hip and down my right leg all the way to my foot. I am told there is scar tissue build-up in the area causing the nerve pain. I started taking Neurontin in small doses and have built up to 1200mg 3 times a day. I still couldn't walk more than 20 feet without leaning on something, but the pain was noticably less severe. My doctor put me on Trileptal instead, and the first day off the Neurontin was a nightmare...the pain was worse than ever. I went back to the Neurontin immediately. I have experienced some weight gain, but have attibuted that to no exercise. It does seem to make me forgetful, tired and somewhat depressed, but without it, the pain is completely debilitating. I want my life back, but I don't know what to do from here. Neurontin has helped the pain to a more tolerable level, but if I still can't even walk, I'm not even close to functioning normally. If anyone has a suggestion, I would love to hear it...thanks.