2.5 year old, milk drying up?

Ive been nursing for 2.5 years, my son nurses a lot throughout the day and night… I’ve attempted to start weaning but he has an absolute conniption. The last two days he’s so frustrated saying “no milk in there” like there’s no milk coming out. Is it possible for your supply to just stop? Especially when he nurses so much? Anyone else experience this?