EXCLUSIVE: Teddi Mellencamp's Devastating Cancer Battle — 'RHOBH' Alum Forced to 'Pause' Treatments Due to Intense Side-effects as She Continues Fighting for Her Life

Real Housewives of Beverly Hills alum Teddi Mellencamp is being forced to pause her immunotherapy treatments because of the intense side effects, RadarOnline.com can reveal.

Mellenchmp, 44, who's battling stage 4 cancer that's metastasized to her lung and brain, quit the therapy after it caused debilitating fatigue.

The good news is "everything's looking good, everything's shrinking," she said.

Earlier this year, Mellencamp revealed she was diagnosed with stage 4 cancer.

Since then, the reality star has been sharing health updates – including the good and the bad – with fans on her social media accounts.

The reality star alum shared an update on her health during a recent episode of the Two T’s in a Pod podcast about her decision to pause her immunotherapy treatment.

Mellencamp said: "Essentially, I haven’t been feeling good for about a month, which was kind of shocking to me, and I think, mentally did a lot to me."

However, after things took a turn, she explained: "Why do I feel like I can barely open my eyes or keep my words straight?"

Doctors then suggested the reality star pause her treatments.

Recently, for the first time, the former reality star has seemingly confessed to having a much-rumored affair during her marriage to estranged husband Edwin Arroyave.

A few months before revealing the heartbreaking diagnosis, Mellencamp announced her split from Arroyave last November after 13 years of marriage.

Since then, she has kept quiet about the alleged affair with her then-married horse trainer, Simon Schroeder, until she finally opened up on the latest episode of The Jamie Kern Lima Show podcast.

The reality star said: "I've never talked about it at all, just because of the kids, and I've never wanted anybody to have a guarantee whether it happened or didn't happen, but what I can say is, did I do things that hurt other people? Yes."

"To this day, does it still hurt my heart, and I wonder if that's why it got cancer?" she asked. "Yes, like it was my payback."

Mellencamp added: "Nothing goes without payment."

During the podcast interview, Mellencamp seemed to have put the blame of the affair on her cancer diagnosis, using her disease as an excuse for things she did "out of (her) better judgment."

Mellencamp explained: "I think I was so sick during that stage — ’cause remember how I told you there were months of headaches and stuff like that — I was looking for comfort anywhere I could get it.

"I felt so much pain. I felt so sick. I didn’t go to the doctors. I just felt some certain kind of way, and the pain was so much that I had gotten to the point of, like, almost hating waking up in the morning, which I had never been that kind of person."