ET EXCLUSIVE: Robin Roberts: I Felt I Was Dying

ET's Rob Marciano sat down with Good Morning America co-anchor, Robin Roberts, on the first day of her return to the co-anchor chair after a 6-month absence after undergoing a bone marrow transplant for a rare blood-and-bone marrow disorder, where she candidly discussed her painful recovery -- specifically a day in her treatment when she felt as if she was dying.

"It’s crossed my mind. It’s hard not to," she said about how often she thinks about that particularly hard moment during her recovery from myelodysplastic syndrome [MDS]. "It wasn’t that long ago. We keep talking about the passage of time and my family loves to say, 'This too shall pass' and that moment did pass. It's not quite in the rear view mirror just yet, but it's getting there."

Related: Robin Roberts Returns to 'Good Morning America'

She also discussed her internal struggle on what to share, and what not to share, with the public.

"I remember giving permission for cameras to be there because I would ultimately have the say. You do struggle with: How much do you show? How much do you pull back the curtain?," she told ET about Good Morning America's documentation of her road to recovery. "I know we’ve done a really good job to help educate people and just bring about an awareness but I've got to tell you, I was watching a few of those cuts and going, 'Wow, I think I had on my suit of armor' at that time."

Related: Celebs Tweet Their Support for Robin Roberts

Roberts' return was celebrated by the show's fans Wednesday, and she expressed her gratitude on-air.

"I keep pinching myself and I realize that this is real. This is really happening," she said on the broadcast. "Faith, family and friends have brought me to this moment and I am so full of gratitude."