In a preview for the singer's new interview with Australia's "Sunrise," Celine discussed her journey with the rare neurological disorder -- which causes painful spasms and muscle issues -- and she confessed it's taken a major toll on her 3 children.

Although Celine had been private about her health struggles until announcing her diagnosis in 2022 ... she now says her kids with late husband René Angélil have had a front-row seat to her illness ... and it's left them terrified.

She explains ... "My kids are scared because they lost their dad, and they're wondering if I'm going to die. I don't want to die, I don't want to lie ... I got scared. It can be life-threatening. What's going to happen?"

As Celine's parents are no longer alive, she has had to rely on support from her friends, including singer John Farnham.

Celine is set to speak out more in-depth about her journey in her new documentary, "I Am: Celine Dion," which arrives on Prime Video next week.

She also spoke with NBC's Hoda Kotb this week, where she admitted to taking near-lethal doses of Valium to help treat her condition ... not realizing how dangerous that was.

CD credited the pandemic with motivating her to wean off her 90 milligrams-a-day dose. Unfortunately, it was at this point her SPS symptoms got a lot worse ... prompting her to share her diagnosis publicly.