Hello there.
I can understand your concern.
First let me correct you , you have
Thyroid since birth. . Thyroid is a gland which everyone has. You have hypothyroidism.
Secondly, your thyroid isn't 16.5 ,
TSH which is called the
thyroid stimulating hormone is 16.5.
Get it checked out by a endocrinologist in person for further evaluation and management.
Best regards.