Weight Goal Smashed!

So today I hopped on the scales to find that I'm exactly 66kg! I'm now at the weight I set as my goal weight for the entire 12wbt with a loss of 800g this week & 4kg overall. According to my wii fit my BMI is 21.31 but I checked the 12wbt charts & it seems to suggest that my BMI is 20.8. Quite frankly I'm really thrilled that I managed to drop to this weight before the actual program started; My first instinct was to eat as much a possible before the 'real program' began but I showed self-restraint & it really paid off. Now my main issue will be trying to maintain the weight---- this will mean eating about 300 calories more than I am at the moment. I tend to swing from one extreme of eating to the other so adding this amount to my diet will be difficult for me. I don't really want to lose any more weight nor do I want to gain any!