Kate McCann has said she was stuck in an "endless bad dream" and haunted by visions of her missing daughter Madeleine after her disappearance.
In a personal account of how the three-year-old vanished on a 2007 family holiday to Portugal, Mrs McCann described how she immediately feared that the youngster had fallen victim to a paedophile.
In an extract from the book, which is entitled Madeleine and released next week, the 43-year-old said: "The truly awful manifestation of what I was feeling was a macabre slideshow of vivid pictures in my brain that taunted me relentlessly.
"I was crying out that I could see Madeleine lying cold and mottled, on a big grey stone slab. The pictures I saw of our Madeleine no sane human being would want in her head, but they were in mine. I simply couldn't rid myself of these evil scenes in the early days and weeks."
The book's release comes almost four years after the three-year-old vanished. It was written by Mrs McCann using her personal diaries. In another extract, serialised by The Sun, Mrs McCann revealed that her husband Gerry was also wracked with similar harrowing thoughts and visions.
Mrs McCann wrote: "I asked Gerry apprehensively if he'd had any really horrible thoughts or visions of Madeleine. He nodded. Haltingly I told him about the awful pictures that scrolled through my head of her body torn apart. I struggled constantly to think nice thoughts and drift off to sleep, but the demons had me in their grip and would torture me mercilessly with images too frightening and painful to share."
Mrs McCann, from Rothley, Leicestershire, also lays bare how she wanted to kill and "inflict the maximum pain possible" on the person who had abducted her daughter. The book also criticises the Portuguese authorities, who shelved the investigation into Madeleine's disappearance in July 2008, for failing to investigate other alleged child abductions thoroughly.
It also documents the moment Mrs McCann discovered that her daughter had vanished from their apartment in the resort of Praia du Luz and the frantic search that ensued. The former doctor, who had been dining with her husband and seven friends at a tapas restaurant 100 metres from the youngster's room, said: "When I realised Madeleine wasn't actually there, I went through to our bedroom to see if she'd got into our bed.
"On the discovery of another empty bed, the first wave of panic hit me. Nausea, terror, disbelief, fear. Icy fear. Dear God, no! Please, no!"
Proceeds from the 384-page book, which Mrs McCann has written herself without the aid of a ghost writer, will boost the dwindling fund to search for her daughter.