i'd be careful sus.
few too many CNS depressants in the mix there...
i find phenibut is quite useful, but it's long halflife leaves me feeling fuzzy the next day. i think the info above posted by meatbag is useful - that people dose this stuff too high. this was probably my problem - i have a stash of phenibut but i've only taken it a couple of times. a good thing to have around, but not to take regularly IMO.
for alleviating anxiety, the dose you took should be sufficient, but just be patient with the onset and gauge it before taking something else.