I'm no dieting expert, but I've lost around 15 lbs since January, and I'm 15. My mom said it's MUCH easier to loose weight when you're younger and I'm at the perfect age. I've only lost 15 pounds in 7 months, so don't feel bad about loosing 1.8 pounds in a week. I think that's a pretty good start, and you're right it's definitely something! Congratulations, and I'm rooting for you all the way!! Swimming IS the best excerise, since you're using all your muscles to swim. Keep it up!