Welcome to HCM,
Your 50 kg weight is not more at this age so need not reduce your weight.
What you require is go for abdominal recti muscle exercise daily and regularly.
Keep your both arms on the chest and raise your one leg up and straight,keep it for few seconds and bring down,do same thing with second leg.
Go for this exercise 10 mint in the morning and evening,
Take less fat and carbohydrate
Ok and bye.