vilive

That's pretty much it. I have no clue what might have happened. I closed the main water valve because of a small leak. Someone in my house forgot not to use the toilet twice so I wanted to temporary turn the water back on to flush, but after reopening the main valve there's barely any water. Doesn't even register on the water meter. What could have happened. It doesn't feel like the main valve broke, could it have?

WhiteTiger

Sounds like you have a gate valve, and you snapped the stem when you turned it off. The valve needs to be replaced.

Redwood

WhiteTiger probably hit the nail on the head with 100% certainty, if the handle just spins and spins without doing anything it's a gate valve...

Another possibility more remote is a globe valve where the washer came off and is crammed in the seat without enough pressure to force it out...

Either way you need the water shut off at the curb which most often requires a special "Key." In many areas the water purveyor should do this as they often go along the line of "You broke it you bought it." and if you touch it they will charge you to replace it but if they break it they fix it without additional charge...