there is nothing you can do now but to hope nothing bad happens of this.
i'm not trying to make you feel bad or anything, but remember, when you buy a fish, its your responsiblity to take care of it for its lifetime as good as you possibly can, and that means don't release it, that does terror to the ecosystem and is how fish get banned which really screws everybody over.
if a fish is becoming too much, sell it, give it away, contact monster fish rescue.
i'm not trying to make you feel bad or anything, but remember, when you buy a fish, its your responsiblity to take care of it for its lifetime as good as you possibly can, and that means don't release it, that does terror to the ecosystem and is how fish get banned which really screws everybody over.
if a fish is becoming too much, sell it, give it away, contact monster fish rescue.