God, I feel awful. Making supper for Ds 21 months and like a twat I picked up a pan that had been in the oven and screamed in pain. Ds thought this was hilarious and started laughing. I got down to his level, told him it's not funny and smacked him on the arm. He looked so shocked and burst into tears. I don't know what came over me. I'm not a person to loose their temper or even shout at all. He's now happily eating and chatting away to me and although it seems he's forgotten already I certainly haven't. How can I make sure this doesn't happen again?