bless you @marizen for you have been loved.
i haven't been to your house and neither have i met your parents.
but perhaps, at your home, while growing up, you have seen LOVE and somehow your parents purposely took time to teach you "how to show", "how to say", "how to act" and "how to share" LOVE.

many don't have that, and so yes; it is difficult to say 'i love you'.
for they do not know truly the meaning and how it is said and how to act it.
and when they try to say it, the actions aren't the same, the mind is not the same. the results damaging.