Do not beat yourself up; we have all probably done something like this at one time or another.
Heck last night one of my partners (and a good friend) blew his whistle to stop play after a FT to bring in a sub. Then he yelled
"SUUUUUBBB!!!" and no one was at the table. My other partner (another good friend of his and mine) started laughing at him big time without losing it all together. Because everyone was looking around trying to figure out who was at the table. And we clowned on him the entire way back from the game about what he did.
To his credit this was a doubleheader and this happen during the JV game. One of the kids started to go off the bench and go up some stairs to go with the varsity team. He saw this and assumed this player was going in the game. But when he blew the whistle, the kid was long gone (up the stair and out the gym). And this is a very experienced official and we had a very good laugh about the situation. You have to be able to laugh at yourself and have fun sometimes.
Peace