You are taking a pretty small dose of gabapentin. I am not a doctor but in 2016 I had a case of phantom smell so bad I couldn’t eat or drink. I went from healthy to bedridden sick on and off for seven months. I lost over thirty pounds. I went to Mayo Clinic in Florida (don’t go there) five times and to Cleveland Clinic. I lost my job of 27 years because I was so sick. It came and went for seven months. My point to you is throughout this ordeal I was taking gabapentin for another issue for fifteen years and a way bigger dose. I don’t know if the gabapentin can cause that but my guess is it isn’t that. What ended up helping me with the smell problem was an anxiety drug called clorazepate. I was prescribed it for anxiety because I was a busy 58 year old commercial office space manager, designer and general contractor and what happened to me including the smell issue stopped me dead in my tracks. No one was ever able to tell me why or what but it was in the brain not my smell.