Hi Hema ,
You are having hormonal imbalance which is affecting your metabolism.Don't loose heart . Take proper medical consultation and treatment.Till then avoid chips ,cookies,butter,egg yolk, and other non veg and fatty food items.Avoid all type of sweets and sugars like chocolates,candies, desserts,puddings,ice-creams.Include as much fibre as you can in your diet avoid refined foods like bread,maida,biscuits etc..Drink warm water after meals.Increase your physical activity.Start with brisk walking.Gradually increase the timing.Little change in diet and lifestyle and proper medication will help you a lot.