Dont be crushed.
People do not know what you have been through and how small your baby initially was.
It is natural that people describe them as tiny as they really are smaller then a full term baby. To you the baby is "huge" compared to what he or she was at birth, so you have a point of reference, other people do not. I am sure they all mean well. The only important fact is how joyful it is to be home with him.