Oh Tan sweety it's these damn May babies!!! DD is exactly the same. I could have written your post word for word. Just the other day I was in tears sobbing about the type of mum I am being. I absolutely hated it and hated the way I was talking to DD. I'm a horrible mum and if Olivia won't go to time out I put her there. She does the same as Iz and throws a tantrum/cries/wants a cuddle but I stick to my guns and make her sit there for the three mintues.
I'm so sorry but I'm of no help with suggestions as I'm as lost as you are. I am going to look into the Magic 123.

PS - you need to change your ticker because there is no way our little girls are four soon!!!!