I weighed less when I got weighed this week with anorexia?

Loosing such tiny amount of weight happens to everyone, as long as you keep eating as well as it seems you are I wouldn't worry if I were you. Loosing or Gaining between 1-2 kg in a few days is normal. If i weigh myself in the morning I'm 59kg, in the evening I'm sometimes 62kg. This just has to do with day to day change. Some days you may be more bloated, some days you may retain more water. This is why you should always weigh yourself in the morning, naked, after going to the bathroom and before eating anything. If you continue to loose weight on the same diet then you can always ask a doctor if you should be concerned.