Good luck and stay strong! It's weird that you're pretty active - I'm not active at all, but I can see sticking to a diet more easily. Just knowing that I want to lose weight, it seemed that food was in the air the entire ride home yesterday. I smelled every fast food place I rode by and it was torture.
It amazes me how the US is - they put so many temptations out there, it's hard to stay disciplined.