@Nammu what dose of gabapentin are you on? I've found it pretty consistently good for sleep. I take 1200 at 8:30 with my other meds and then 500 mg more at 11:00. Even that is not a low dose; I've been on 2700 mg before in the hospital and just after coming home. I did have to find the exact right dose for it to work and that took some jiggling.

I hope you get some sleep.