GABA on low cortisol

Hi.I tried GABA for the first time few days ago and it works!I began to sleep 6-7 hours!For the last 5 years i sleep only 3-5 hours maximum, i just wake up and cant fall asleep anymore.
So gaba helps to stay longer in sleep but i feel fatigued as hell!And bruises under the eyes are much darker,and low back pain is harder...
I'm sure that my cortisol is low(although i didn't check it ).
I have the same fatigue if drink melatonin,L-glythamin and any adaptogens(that means they lower cortisol).
So whats up? Does gaba lower cortisol somehow? It is very sad because i sleep with it,and also it helps to reduce racing thoughts. Mb i should continue drink it anyway?Any thoughts would be appreciate. Thank you. Tweet