Selma Blair holds son Arthur tight amid emotional journey with MS

(CNN) -- Selma Blair holds her son Arthur close as she shares more about her struggle with multiple sclerosis.

The two hugged in a new Instagram photo as the actress explained that "It is darkest before the dawn, I have always heard."

"I keep it in mind. And I still get overwhelmed in the chaos of the dark. And I am so deeply moved at how many people called or wrote or left comments after my last post," read her caption.

Blair recently shared that she had lost her hair as a result of some of her medical treatment.

"The old me was ashamed," she continued. "Ashamed to be so transparent with vulnerability or fear. And I wanted to delete the image. The heart bruised words. But you all changed that with your words of support. I was humbled ... Maybe I will print and put in a book for when I need it again."

Blair added that she "failed as a mom a million times yesterday" but "Arthur was fine."

"The world didn't stop," she said. "I cried. He laughed. He played a fishing video for me. We slept and woke and he took this. He is golden. Alive. Happy."

"Thank you universe. I will get there. Have patience. Thank you. All of us. Be gentle. With ourselves and others. It is a wonderful feeling. Thank you to everyone here and in my life who did that for me the last few days. I can do this now," she concluded, adding the hashtag "#walkingeachotherhome."