The ‘Real Housewives of Beverly Hills’ alum opened up about the emotional toll of living with cancer and how her dad, John Mellencamp, lends his support.

Teddi Mellencamp on The Jamie Kern Lima show.Credit : Courtesy of The Jamie Kern Lima Show

Teddi Mellencamp said that she’s focusing on “belief,” not fear, amid her stage 4 brain cancer diagnosis — which she’s been given a 50-50 chance of surviving.

The Real Housewives of Beverly Hills alum, 44, described the emotional toll of living with cancer to Jamie Kern Lima on the July 29 episode of her podcast, The Jamie Kern Lima Show.

“There’s a sense of sadness that comes along with not feeling your best,” Mellencamp said. “The dips, the highs and lows, the unknown.”

The reality star — who has been documenting her ongoing melanoma diagnosis after undergoing 17 surgeries for the invasive skin cancer — confirmed in April that her disease progressed to stage 4, having metastasized to her brain and lungs. She needed immunotherapy, radiation and surgery to treat the tumors.

“I would be lying if I said I also didn’t have a little bit of anger. Why did this happen to me?” she admitted to Lima. “In my mind, I was so healthy. I was taking care of myself. I play sports.”

Teddi Mellencamp and Jamie Kern Lima.Courtesy of The Jamie Kern Lima Show

Now, Mellencamp said she has been sidelined from many of her favorite physical activities, as the side effects of treatment have been rough.

She explained how much her father, John Mellencamp, has helped her with things she “wouldn’t be capable of doing.”

“He has been beyond,” she said. “With all of these medical treatments and everything. He has stepped in, he’s helped me have a nurse … he calls me every single day. He makes sure that I’m okay.”

Mellencamp recalled how, at first, the gravity of her illness hadn’t sunk in: “We thought, ‘Oh, she’ll just have the surgery and she’ll come out and she’ll be able to manage things’ … and I most certainly can’t.”

She couldn’t imagine what her new life would look like.

“I was so scared to go home and not be the me that I was when I left home. It was frightening. And so that’s when [my dad] was like, ‘Let’s get you a nurse. Let’s get you set up.’ “

When she got home, she was “so weak, I couldn’t give myself a bath. I couldn’t take a shower. I had ginormous holes in my head.” Her dad’s support was crucial in those early days.

He also taught her, “it’s okay to have an emotional day.”

She reiterated the importance of that lesson to Lima. Their interview was five days after Mellencamp’s latest immunotherapy treatment, which tends to bring raw feelings to the surface. “I have it once every three weeks and it’s my most emotional day,” she explained.

She told Lima she she nearly canceled the appearance because “I know I’m gonna get upset.” But ultimately, Mellencamp decided to go through with it: “People need to know it’s okay to be upset.”

This prompted Lima to ask “How much of your energy goes to fear and how much of it goes to full belief?”

“I would say a lot of my energy, it goes to belief,” Mellencamp said, while admitting to feeling disappointed about no longer “hopping right up” in the morning to work out and to get her kids, Slate, 12, Cruz, 10, and Dove, 5, whom she shares with Edwin Arroyave, off to school, as she did for years.

“I have no routine anymore,” Mellencamp said, sharing that cancer was “a big wake-up call that life isn’t perfect.” But she also realized, “You don’t have to be perfect, you just have to show up.”

Mellencamp said her positive attitude is what keeps her going. “I have to keep fighting. I can do this,” she said.

“What is the prognosis right now that doctors say?” Lima asked.

“I would say probably 50-50,” Mellencamp said. “But like, I truly believe this when I say this — and it’s gonna make me emotional — I truly believe that I’m gonna live. I need to believe it. ‘Cause if not, it’s just too sad.”