Is it shm or smh?
The correct text abbreviation for “shaking my head” is SMH, not SHM. Use “SMH” in text messages or online chats when you want to show disappointment, frustration, or disapproval about a situation (e.g., “The squirrels ate all our tomatoes again. SMH”).
If you’re ever looking for alternatives to “shaking my head,” the QuillBot Paraphraser can show you different ways to say the same thing.