I wonder what dosage your doctor was giving you on the amitriptyline and nortriptyline? (Dosage for treating PN is usually much lower than the standard dosage used for depression.)

As for gabapentin, everyone's experience is different. I've been taking it for almost a year and a half. In my case, it is very effective for controlling twitching and cramping - so it might work for your "spasms". For me, the side effects aren't terrible - it's somewhat sedating and it does have a negative effect on libido. (I am male, so not sure how it might affect a female in that regard.) All in all I'd rather not be taking gabapentin - but the benefits are outweighing the side effects for me right now.