How to say "I love you!"?

I'm not very good at expressing love, especially the declaration of love. Sometimes I feel the words are too cheesy, other times too emotional. I guess as a new romantic writer, I should learn more about this art, of talking about love.

Here a few from my books. How do you think I fare? Of course, you can see some are borrowed/inspired by Jane Austen's words.

She thought of his love with a deeper sentiment of gratitude than she had ever felt before; she remembered his gentlemanly ways, his warmth, and the caring manner that softened the stiff, reserved way in which he had expressed himself in times past.

She was thankful for the strength of his love, a love which defied his own will, persisting against his reason and perhaps even against his character. She was grateful to him, not merely for having once loved her, but for loving her still. - Bargain with the Devil

She and she alone made him feel complete. - Really Angelic