GABA aka gamma-aminobutyric acid is NOT GabaPentin. GABA is the skeletal building block from which GabaPentin, PreGabalin/Lyrica and Baclofen are derived. Note that GABA is contained within the names of GabaPenti and PreGabalin.
https://my.clevelandclinic.org/health/articles/22857-gamma-aminobutyric-acid-gaba
https://www.medicalnewstoday.com/articles/326847
I tried it years ago, but don't recall much in the way of anxiety relief. You can pretty much take it in unlimited amount from what I remember, but not if it's the form with inositol in it. One recommendation was to open say the 1,000mg capsules and dissolve the contents in a small amount of warm water first. If you try it, then try it slowly to to see how you might react and maybe slowly increase the amount if you feel any benefits.