ABC News' Cecilia Vega reports:

"Real Housewives of Beverly Hills" star Yolanda Foster is battling a case of chronic Lyme disease so severe, she's put her mansion on the market for a reported $27.5 million to minimize the stress the debilitating illness has caused in order to focus on her recovery.

"Lyme disease has really severely attacked my brain," she explained on Bravo's reality TV show, first announcing her diagnosis in December 2012.

Lyme disease is carried by ticks, which after a bite can enter the bloodstream, attacking the skin, joints and nervous system. Foster is not exactly sure how or when she contracted it.

"It's such a lonely disease, and it's so silent," Foster, 50, told ABC News. "It started with memory loss and difficulty focusing. I couldn't read or write, or watch TV or do anything."

The recovery has been painful for her, from having a port implanted to get antibiotics into her bloodstream quickly, to visits with doctors around the world. The Dutch model, married to Grammy-winning musician David Foster, even underwent a clinical trial with machines she says help repair damaged brain pathways.

"Another day at the office…… Dealing with the important things in life! # WeMustFindACure ," Foster tweeted on Jan. 16, showing a photo of the clinical trial's machine attached to her head.

But she's hardly alone. The CDC estimates there are about 300,000 new cases of Lyme disease every year in the United States.

"I get emotional just thinking about it," Foster said with tears in her eyes. "How am I going to get out of this?"

And even though she is getting better, Foster feels she can no longer manage the couple's stunning 12,000-square-foot mansion. Reality TV's perfect pad is just too much work for her in her new real-life reality with Lyme disease.

Foster put her dream house on the market for a reported $27.5 million.

"I really am not that attached to materialist things," she explained. "I can make any house a home."