Bye bye bengaii

[Chase31]

well i had my bengaii (lukus) for about a month maybe more, i never ever saw him ea., always hung out near the bottom of the tank and he was getting less shy still not eating.
Then one day i came home and he was stuck a little in the overflow sideways, he was still alive so i put him in the freezer to put him out of his pain.
He wasn't breathing hard or anything.
Was i wrong to assume he was dying? and if he was why? was it cuz he wasnt eating or what??