Nutmeg is a drug. It is a psychoactive drug.
Deaths are extremely rare (but according to Wikipedia there have been at least two in recent years).
My mother told me that a whole nutmeg would "probably kill me" - that was the greater part of 60 years ago.
It almost certainly won't, but it won't be an experience you'll want to repeat.
If you think you have eaten too much, get to a doctor now.
