you're still teaching zumba twice or three times a week, are you doing any running? I wouldn't cut calories any more - in fact, i'd be tempted to go for more food.
if you think - they don't recommend step one to nurses, because they're on the go all day, and i reckon you do loads more than that.
thing is - there has to be a reason for it. you're not a freak of medical science, and you're on a vlcd. if you're not losing weight it won't be because you're having too many calories, it might therefore be that you're having too few.
or it might just be that at your current BMI your weightloss will be slow. I don't lose at the rate you've set for yourself, and i'm still at the top end of obese.
you have a beautiful new red frock that you look gorgeous in now - why beat yourself up over this target? whatever will be, will be: you can't force your body to fit in with your plans - and in the meantime, please be kind to yourself, petal.