Diana...

It's not the end of the world. Yes, you went overboard on the nuts, but it's eaten and whatever damage you did (which I'm willing to bet will be small and only result in some water retention) is done. Drink plenty of water to counteract all that salt and pick up where you left off tomorrow.
As for why....you're the only one who can answer that. Everyone gets a case of the munchies now and then and I can see where it would be very easy to eat that many nuts if you aren't paying attention to how many you've had.

BTW...are nuts the only thing you've had to eat today? If so, I can understand why you would have eaten all that...you were hungry!