Firerose feared she wouldn't "survive" her health battle amid her messy divorce from Billy Ray Cyrus.
The 36-year-old singer has had a tough time this year, after splitting from Cyrus in May following less than a year of marriage.
Firerose also discovered she carried the BRCA1 gene - a mutation that makes her more susceptible to developing breast and ovarian cancer. Doctors recommended she undergo a double mastectomy and subsequent reconstructive surgery.
"There's been a few times I wasn't sure that I would survive," the star, whose real name is Johanna Rose Hodges, told Us Weekly. "It was a very humbling experience that put everything into perspective."
In the new interview, Firerose also revealed she developed pulmonary embolisms in both of her lungs.
In September, the Australian star announced she had been rushed to hospital with a "life-threatening diagnosis". At the time she didn't give any other details about her condition, but shared via social media she felt "grateful to be alive".
Firerose returned home after spending five days in hospital and she has now recalled how the enormity of the situation left her shaken.
"It's a very serious thing that can happen and easily can be fatal," she revealed.
Firerose and Cyrus married in October 2023, with the Achy Breaky Heart star filing for divorce citing "inappropriate marital conduct" just seven months later.
Firerose has previously claimed she was forced to postpone her double mastectomy when 63-year-old Cyrus filed for divorce 24 hours before she was due to undergo surgery in May.
