I have never been on Neurontin, but I have heard it does work for some people and not for others. It's main use is not as a mood stabilizer, so it may not work in the same way the ones that are do. Also, it seems like you are taking a low dose, so I would give it some time and see where things go. I have switched meds 3 times and I sympathize. Good luck with everything, let us know how things are going.
"Don't let your yesterday ruin your today."