I'd guess your calculations are incorrect.... or you're sleep eating. At such a low calorie intake you should be dropping pounds and be stupid-confused.

People managed to starve to death.... long before any fad diet... let alone the latest fad diet. Try switching foods. Change things up a bit. But anything below 1000-1200 calories is just asking for complications.

Humans are bio-mechanical machines. If you expend more calories than you consume you will lose weight. Just like cars burn gasoline... people burn up food. Eat less food than you burn... and the result is weight loss.

Think healthy. Drink plenty of fluids get a full eight hours of good sleep.