Don't be so hard on yourself to lose weight. Vitamin C supplementation is not good for your health. The best thing is that lemon slices soaked in water can really lose weight and have whitening effect, so you don't have to buy any brands specially. My way to lose weight is not to eat staple foods such as rice and flour, but also to eat potatoes and vegetables such as vegetables, tofu, onions, mushrooms and carrots. Besides, I do aerobics and run, as long as I keep on losing weight quickly.