If you have notes synced across your devices, and have an iPhone, then go to your iPhone in settings, turn on Airplane Mode, and go into Notes. Maybe by some miracle it won't have synced yet and the note will still be there. Just make sure you're completely disconnected from the internet before opening notes at all. Unless you already opened notes since. In which case, yeah, you're SOL.
It's a crapshoot at best but the only shot.