If you live in London go to a Snog, a small serving of Milk Chocolate is only approx. 120 calories and it's yummy and really creamy (I don't know how they get fat free yogurt sooooooooo decadently creamy). It's my go to when I crave chocolate. They closed down my local Snog parlour, but I'm willing to make the trip to Selfridges or Covent Garden to get one. I can't tell you just how amazingly good it is.
PS I'm just assuming you live in Britain please excuse me if I'm wrong.