Hi Alexa,
Jut wondering are you actually eating all of your daily cals? Perhaps you could try to swop your main meal around to lunchtime which would hopefully fill you more. Not sure if this is allowed but sometimes I do and have noticed by tea time I am not that hungry, so a salad and fruit fills me. Some days I can't eat all of my 1200 cals. Are you drinking plenty. I find a can of diet coke helps to sip in between meals along with a glass of water about every hour. I am sure others will suggest ideas.
My first week last week I was disappointed as I didn't loose anything but this week I am really doing a lot more exercise in way of walking, DVDs and generally keeping busy.
Post how you are getting on as the days go.
Good luck x