Just when Grease star Olivia Newton-John seemed to have fully bounced back after her battle with cancer in 2017, she revealed that things haven't gotten better.

Last year, the Australian actress was forced to cancel a number of tour dates due to health issues, which were believed to be complications related to a sciatica flare-up.

Unfortunately, a few weeks later, it was confirmed that she had been diagnosed with cancer for the third time in nearly three decades. She was previously diagnosed in 1992, and had to go through nine months of chemotherapy, a partial mastectomy and breast reconstruction surgery.

The 69-year-old's breast cancer relapsed again in May 2017, and "metastasized to the sacrum [base of the spine]," according to the somber, albeit hopeful, announcement posted on her official Facebook page.

In the post, the entertainer opened up about her treatment plan, which included "a short course of photon radiation therapy," as well as "natural wellness therapies," which included tinctures of medical marijuana to manage the intense pain.

Three months later, Newton-John shared an update, reassuring fans that she's "feeling great."

"Your prayers and well wishes have truly helped me, and continued to lift my spirits," she said in a video message. "I'm feeling great and so look forward to seeing you soon!"

A year later, the Physical singer appeared to be healthy and remission alongside co-star John Travolta while attending the Academy of Motion Picture Arts and Sciences' screening and Q&A celebrating the 40th anniversary of Grease on August 15.

Unfortunately, during a very recent interview with Sunday Night, the Grammy winner revealed that she is still battling cancer.

Newton-John told journalist Alex Cullen that she tries to not let her third cancer diagnosis scare her, and having the support of her husband helps her overcome the fear.

"My husband's always there, and he's always there to support me, and I believe I will win over it and that's my goal," she explained.

The singer, who turns 70 on September 26, said although she's using "modern" medicines, she's still relying on natural remedies to treat the disease. She added that she has cut sugar out of her diet and is still using cannabis for pain relief.

Newton-John's husband, who founded the Amazon Herb Company, has been growing the marijuana at their California ranch.

"In California, it's legal to grow a certain amount of plants for your own medicinal purposes," she said. "I'm very lucky that I live in a state where it's legal and that I have a husband that is a plant-medicine man."

Much to many people's surprise, Newton-John explained that this is actually the third time she's fighting cancer. In 2013, after a minor car accident, tests revealed that the cancer returned and spread to her shoulder.

She didn't go public with this diagnosis because she wanted privacy.  She told Cullen: "I thought "˜It's my life' and I just decided to keep it to myself."

Despite her failing health, Newton-John hasn't stopped advocating for breast cancer, and is currently running a cancer and wellness centre based in Melbourne, Australia. Last year, she launched the "We Go Together" campaign with a goal to raise $1 million "continue to grow our critical research, pioneer trials and deliver holistic care to all who are in need."

It's never easy to deal with cancer, but Newton-John has already beat it twice, so we are confident she can do it again. We're wishing her a speedy recovery!