I was put on gabapentin again for Post Herpetic Neuralgia pain, I cant remember how long before it starts to work if its gonna work this time around, Im on 900 mg at the moment but am working my way up to 1800mg, also is dizziness and headaches a side effect? Its got to be because I feel so weird every time I take it and I don't remember this happening last time, thanks in advance for those who reply ...