With your height, at least fifty dollars. Eat healthy foods, exercise (swimming, kayaking) or gardening. Don't listen to showmen - they are pedophiles. Remember: you won't be a girl. Get ready to become a mom - from one happiness to another. And then there will be happiness ... You know yourself
Apparently the body resists, senses something amiss, has turned on the economy mode. Over time, of course, he will give up, the law of conservation of energy has not been canceled. But there is a great risk that you will ruin your health with such a regime.
If we leave aside the normality / abnormality of 40 kg (I do not know), then it is recommended for small people to lose weight normally with a calorie deficit of 200-300 per day, so that the body managed to adjust. With your parameters, this is ~ 1000-1200 calories per day of food (if without active training), and not 400. Of course, the process will take longer. But it is safer for health.
Why? "Show the world your bones"? You do not lose weight, but you need to get better, up to 50-53 at least.
If you do not like how you look in this weight (healthy for you), you most likely have body dysmorphic disorder, and even anorexia. Here you need to contact a psychiatrist (or a psychologist at least), and the sooner the better.
Health to you!