im 13years old
i weight 48.0kg very much im 160cm tall
and you your weight is very much as well
althought i think one of the problems that your weight is going down is because of your family genes
if your mom is not thin or dad or one of your relatives that must be from family genes
but if you have thin people in your family that are thin its not from genes its from other things
like me i thought i had big theighs
but when i lose weight it was just big bones!!