Tell how~ so that~

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Mildred sent him a postcard to announce her safe arrival, and he snatched half an hour every day to write a long letter to her. He had always a certain shyness in expressing himself by word of mouth, but he found he could tell her, pen in hand, all sorts of things which it would have made him feel ridiculous to say. Profiting by the discovery he poured out to her his whole heart. He had never been able to tell her before how his adoration filled every part of him so that all his actions, all his thoughts, were touched with it.
[Of Human Bondage by Somerset Maugham]
I'd like to know if "how" modified "filled" and "were touched."
Thank you in advance for your help.