Correct. Doctors and nutritionists advise that your weight loss
rate should be no more than 1kg per week.
Think about it: 1kg of fat requires 7000 calories for you to
burn it all up. So in fact, should you lose 1kg per week, only part
of it is going to be fat, unless you happen to be a trained
professional marathoner.
Focus more on losing fat than on losing weight. Eat a
sensible diet and have a sensible exercise plan to go with it.
Small, sustainable goals are easier to achieve than large, massive
goals.
And be patient. You didn't gain all that fat all at once, so you
shouldn't expect to lose it quickly, either.