You don't. You would be awake through the whole painful process. It would be terrifying. If you have poisoned yourself with them, I'd recommend that you go to a hospital right now.
I red somewhere that from heavy dose you fall into unconsciousness.But there is no info when.... it depends on type of pesticide but if someone was super heavily poisoned with that black out type pesticide,how much time would pass before the persons mind will shut down?
You lose consciousness when the pesticide paralyzes your lungs and heart, when your brain stops getting oxygen. Until then, you would be in a lot of pain, and very scared.