I Love Them, But ...

I really love my father, mother and sisters, and I'm sure they also love me, but I've never said, "I love you," to them. I think we don't need to say, "I love you ," because we know we love each other. It is usual in Japan, so when I saw my American friend say, "I love you," to her family, I felt it is strange very much.
When I watched, "the O.C," which is the American TV show, I often heard, "I love you, mom," or "I love you, dad." They were not special scenes such as a wedding. I can't imagine that I say, "I love you," to my family. If my family says to me, "I love you," I'll be surprised very much, because they have never said such a thing. It'll make me ashamed. We don't have such a custom to say, "I love you," so it's difficult to say such words! I think it's more easy to say, "I love you," in English, because I'll be active when I talk to someone in English, and I receive American culture in spite of myself. I think Japanese custom and politeness for my parents, sister or friends make me stop saying, "I love you."
I want my family to know I love them very much, and I really appreciate their supporting me. I think I wish I could say, "I love you," but I don't think it is the best way to tell them directly, so I want to tell them, "I love you," without words as a Japanese!