Knowing how well tolerated gabapentin is compared to anti-anxiety drugs and such, I would ask about increasing your dose of the gabapentin before trying an anxiety med.

Have you stopped all caffeine and any MSG or processed soy? They excite the nerve cells.

Try not taking the Cyclobenzaprine at all.

Maybe the 3x a day dose of gabapentin will help. Or you could take 200mgs of gabapentin before bed and 100 mid-day. It should help you end of day tensions.

Extended maintenance on muscle relaxants can be problematic. Long term gabapentin is not a problem.

My best to you.