So scared!!!! 😢

My doctor told me I have to diet.. (Which that part is fine with me). But they said go on a gluten free, lactose free, and a carbohydrates diet. But I decided to just do calorie counting instead of carb counting. Anyways I'm almost 21 years old, and he said the way I'm going if I don't diet and loose weight I'll have a heart attack by 24 years old and full blown diabetic by 40. I'm on day 3 of dieting and it feels good but I'm scared I won't loose anything. I lost 20 pounds 2 months ago by staying myself, but now I actually have to try and write everything that goes in my mouth. What do I do???? Please HELP!! I have PCOS, insulin resistance, and in Clomid and Metformin.. I'm 5'7, 238 pounds. How much weight do I have to loose to get pregnant? Also I have to loose weight in 3-4weeks how much do you think I can loose in that time?

My doctor basically called me fat to which pissed me off. Even though I'm not "fat" I'm just bigger boned. Am I in over my head? Or what?? I need someone's help. 😢😳😞😣😰