eating too much?

I had my lap band on Aug. 23 '06. I basically haven't lost any weight since my first 2 weeks. I have lost 18 lbs. but then I will lose up to 5 lbs then gain it back. I can't seem to get over the hump. I've had 1 fill and am trying to get another one at 5 weeks before I leave for vacation. I'm eating too much they say at the doctors office. She (the lady head of the program) said I only need to eat 1/2 cup of food at my meal 3 times a day. When I try to do this I starve all day. How can you only eat a 1/2 cup of food and not starve?? All I do is think about food, that why I was fat, about 240 when I had my lap band. I'm hoping after the next fill that I can eat less. I still can eat a lot of food, but not as much as I use to. Beef is hard to eat and pork. My cousin had it and lost from 247 to 128 in 1 year. I wish I could do that well. I haven't started on any exercise and that part of my problem. I've just got to take time for me and do it. I got a set of head phone with CD player so I'll try to get to the gym and do the treadmill. Can anyone can tell me what is good to eat that will help fill you up and not be so hungry. I've been eating peanut butter crackers when I watch TV and get excited with one of my TV shows, whcih is not permitted. So I cheap, another problem. HELP!!!