gnsm

Aka, Good Night So Much. The phrase partly comes from Zied from 90 Day Fiance. Zied used to say "so much" to describe everything.

Gnsm can be used to say good night to someone, show frusturation of an unwanted outcome, or used as a synonym of "RIP" (rest in peace).

You can also add "sm" to other abbreviations that create a similar effect.
glsm : good luck so much
gmsm : good morning so much
etc.

Example 1:
Bob: I'm going to sleep now.
John: Ok, gnsm.
Bob: gnsm.

Example 2:
George: I got demoted out of masters
Randy: gnsm lol

Example 3:
Joey: I just ate 5 spicy tacos. gnsm my ass.