This is what you say when you smh so hard that it's infinite. Here's what the acronym stands for . . .
s - smh m - my
h - head
my - my
head - head
So in other words, directly transalted to English it means, "smh smh . . . my head my head . . ." with each ellipses signaling that it goes on infinitely.
Guy 1: "Hey dude, do you play Fortnite?"
Guy 2: "Smh my head."
Created by the meme god Danny Gallagher smh my head is when smh doesn't suffice to the amount of head shaking required to be disappointed in something.
Bitches don't even pray to god anymore, they just pray to Cardi B, smh my head