“I would see visions, I would hallucinate and I wasn’t able to read. Reading really was my saviour before my illness because I would just block everything out and just read.”
The 34-year-old goes on to explain that the death of her father, Michael, in 2008 was the underlying trigger for her psychosis.
“I am not fully recovered from it. He (my dad) used to come to visit me a lot. I didn't think that he would die and I didn't understand that would be the last time that I would see him,” she says.
“We had been appealing and appealing and then the final appeal came back denied so it was those things that I couldn't get my head around. So mid-2008 I started losing my mind… hallucinating, I couldn't eat.”
Schappelle, who currently resides in the Gold Coast, is one of a slew of celebrities starring in the Channel 7 military-style reality show. As part of the gig, she'll take tests from the real SAS selection process, which will subject her to extreme physical endurance, sleep deprivation, interrogation and psychological testing.
In a teaser for the show, Schapelle, who served nine years in Bali's Kerobokan jail, fights back tears as Chief Instructor Ant Middleton questions her repeated claims of innocence.
“How come a court of law can prove you guilty and then you’re saying that ‘it wasn’t me’,” the ex-Special Forces Soldier prompts her.
Struggling to maintain composure, Schapelle bites her bottom lip, before the video cuts to her bungee jumping out of a helicopter.
Speaking in the voiceover, she says: “I don’t do heights, I don’t do cold. I fear open spaces. I fear interrogation. I’ve been locked away for a very long time… I’m 43 now. I want to change my life.”
In another sneak peek, Schapelle and the other contestants - including PR maven Roxy Jacenko and former Bachelor Nick Cummins - are led through barren terrain in a prison-like procession.
“This is completely unscripted and one hundred per cent real!" Ant says in the voice over.
“We’re going to find out who they really are… and so will they."
SAS: Australia premieres at 7.30 pm tonight on Seven.