From history it seems that you are loosing weight.
First you require to find out the cause of loosing weight.
Consult your doctor and go for investigations and rule out any wasting disease.
If every thing is fine then go for high nourishing food, carbohydrate
Take plenty of milk, butter, cheese, ghee, panier, pulses, cereals, puddings.
These will help increasing your weight and help in building your breasts well shaped, well countered and hard.
Ok and take care.