I can't

Why is it for some people it's hard to say I Love You? Like me. I can't say I love you to my family and to my friends. It's not because I don't love them. I just can't say those words to anyone. Maybe because I am not used to it. I'm not a type of person who is vocal. I usually don't show my feelings to anyone. I hide it in my heart. I'm a secretive person. I think that it is such a shame to say those words. I also think that those words are not just ordinary words and I just can't say it to anyone. I feel like "I Love You" is such a powerful statement that I cannot just take for granted. Even though other people will say "I Love You" to me, I cannot reply.

I am hoping that I can become vocal even a little. Just a little will do. hehehe.

I can't even greet my mother a happy mother's day in person. I can't even thank my parents. I can't even write "I Love you" in a letter.
What is my problem? Is there anything wrong about me? I wish I can show my feelings properly.