I've had gabapentin work differently for me different times.

I was first on it with akathesia/mania combined and I was so sedated I couldn't function and the dose had to be lowered a bunch of times but I stayed of 400 mg for sleep.

When I changed from Seroquel to clozapine I was extremely agitated and unable to tolerate any noise or even conversation. That was IP so they put me on more and increased it daily until I was on 1800 mg/day, divided.

After I was on clozapine a while that was way too much and we backed down slowly to 800 mg at bedtime and 100-200 mg PRN. I've been on that for 2.5 years without issues aside from being too sedated from my entire cocktail combined.

Now my pdoc is hoping to wean me back to 400 or so once summer and my higher risk for mania passes.

It's a weird drug but it has really helped me. When I was IP I kept telling them it felt like all my skin was gone and I was nothing but bare nerves which was intolerable.

My weighted blanket really helps with this if one of those is an option for you.