Hi llenod
I'm not knocking any diet. It's hard to lose weight. I just wanted to throw in a couple things for you to think about. What are your long term plans for when you get to a goal weight? Do you plan on drinking Slimfast the rest of your life?
The reason I ask is because, the "losing weight" part is only part of the picture. Once you hit a goal, you have to be able to maintain that goal forever or the diet was a failure.
I don't think you're eating enough calories. I'd suggest, like snow and Lisi have suggested, that you start by eating around 1500-1800 calories a day. You will still lose weight.
The object here isn't to starve yourself thin. Heck, anyone can do this. The object is to tailor an eating plan that you can live with and stick to the rest of your life. At some point, these shakes will stop and you'll just gain it all back if you don't think about the future.
I'm not trying to change your mind about slimfast.

Just throwing in some "food" for thought. Congrats on your 7 pounds!! Keep up the good work. Eat more food for crying out loud.