Does Gabapentin Take Time To Heal Nerve Pain And Back Injury?

I had a back injury a year ago that has left me with nerve damage from lower back into groin, hips, and legs. I have not been able to do normal daily activitys for a year now due to severe nerve pain. My doctor put me on gabapentin 2 weeks ago Im on 1800 mgs. a day, but there is no change in pain level. Dose it just need more time to work, or is it just not going to work?