This is a little bit old, but I'll chime in. Gabapentin (Neurontin) has a wicked broad therapeutic index. I'm not proud to say this, but I've taken grams upon grams of Gabapentin in single outings on several occasions, either due to tolerance or the intensity of my Opioid withdrawal. Myself and others are limited in our intake by the fact that acute overdoses of Gabapentin - of Pregabalin for that matter - can and do cause some pretty intense, non-epileptic, convulsive activity, ranging from loss of motor control, to full body spasms and flailing sometimes resulting in injury.
For this reason, it's a good idea to not overconsume Gabapentinoids like Pregabalin or Gabapentin, but aside from these side effects, which seem to effect only a minority of the community, these drugs are relatively safe. They're even believed to be essentially safe when combined with CNS depressants (Opioids, Benzo, Alcohol etc.), contributing in only a minor, if any, way to respiratory depression. This argument, with my references, is part of what got me my Pregabalin prescription, despite having a documented history of pretty severe substance abuse; it's practically impossible to kill myself with this shit.
Long in a short, I'm sure OP is fine now, but, acute overdose with Gabapentinoids is definitely not in the same league as say Opioids or Cocaine, so your best bet, if you think you've consumed too much, is to let someone know what's happened, just in case something does go wrong and if you notice a marked increase in negative symptoms, perhaps consult a doctor.