You can do one or the other, you don't have to do them both. You can even eat a few apples a day. The malic acid is in apples.
You can also use applecider vinegar from the healthfood store, in your case may be 1 tbs in a large glass of water 2-3x a day between meals.
Because of your weight I would not use more than 1/2 cup of the oil or try a little bit less. For children it is usually advised to half the amount.