I try to limit my shouting to the witching hour (ie, 6-7pm) when the children are running around like wild animals and I'm trying to clear up loads of fiddly plastic Ikea plates, bowls and every single fork and spoon in the house, while simultaneously running their bath and searching desperately for the matching pink 'teddy bear' pyjamas and keeping baby sister from smacking older sister in the head with the Gruffalo book, when my only real concern is that I haven't been able to locate my bottle opener. Don't beat yourself up! ;-)