Neurontin and zovirax

My neurologist prescribed Neurontin for post-herpatic neuralgia (the pain after shingles). I'm supposed to be taking 2400mg a day, but am only taking 1800mg because the side effects are so bad. I have very bad coordination, dizziness to the point of falling over, spaciness, slurred speech, weird vision problems - its like my eyes forget to focus, my husband says I'm staring off into space alot too. I am a professor, and find that I can't remember words or key concepts while I'm teaching. I can't drive, so my husband has to drive me everywhere. In addition, I've been having very strange thoughts, such as that I am going to purposely crash the car, or that my cat is going to attack me. It is very frightening and I'd like to go off the medicine, but I know it can induce seizures if you go cold turkey. Is this really our only alternative? Either live in unendurable pain, or suffer from Neurontin?