Sarah Harding has recalled suffering "horrible dreams" when she was placed into a coma by doctors.
The singer, 39, is battling breast cancer that has spread to her spine, undergoing intensive chemotherapy to help with her symptoms, and has had a mastectomy.
Before her treatment began, she was placed in an induced coma as her lungs and kidney were failing.
And in her new autobiography, Hear Me Out - which is already topping sales charts - Sarah recalls being plagued by nightmares.
Medical professionals had played her favourite music and TV shows in an attempt to stir a reaction from her.
" I wasn't in that room, however," Sarah writes.
"I was in another world. I remember having the most horrible dreams during it all, but I could never put my finger on precisely what happened in them. Just that they were awful.
"Situations I couldn't get out of, no matter how hard I tried. I have recollections of being on some sort of quest, but not being able to find or obtain the thing I most needed."
She continues: "I remember everything being larger than life and otherworldly, as if I was in a movie like Labyrinth or The Never Ending Story.
"If ever there was a twilight zone, this was it. There was no warmth, no comfort, just fear and a need to escape."
And during the coma, Sarah was unaware of any of the treatments doctors were administering.
"I had no idea about all the things that were happening to me or any of the treatment I was given," she adds.
"Even once I was off the ventilator, I still couldn't speak properly. All I could do was make these noises that sounded like a chimpanzee trying to communicate."
Sarah was first diagnosed with cancer during the summer last year.
It has since spread to her spine, her doctor telling her in December that Christmas 2020 would likely be her last.
"I'm at a stage now where I don't know how many months I have left," she writes.
Girls Aloud bandmate Cheryl has also contributed to Sarah's memoir, sharing that it's a rare moment when her friend isn't on her mind and that news of her illness "hit me so hard."
"Now I just want to be there for her in any way I can," Cheryl tells, "She might want to cry or rant or even have a laugh, but wherever it is, just be there."
Hear Me Out by Sarah Harding is available now.
