The Real Housewives of New York alum hasn't left her husband's side at the Memorial Sloan Kettering Cancer Center in New York City as he recovers from a recent procedure.
"His cancer took an unexpected turn," Zarin said while talking with People. "But he is not going down without a fight."
The 53-year-old reality star says that Bobby's latest setback has had an overwhelming effect on her.
"I'm in shock," she said. "I'm in physical shock. I've lost 8 lbs. already. He was doing well for a very, very long time. Then the cancer came back in his brain last fall and since then, it's been one thing after another."
Bobby was first diagnosed with thyroid cancer in 2009. He had his thyroid removed and underwent radioactive iodine treatment. However, it did not have the desired effect.
"Radioactive iodine treatment works on most patients, but in his case, it didn't," Jill said.
Last week, Jill and Bobby were hit with tough news.
"We found out, after thinking he had pneumonia, that his Papillary Thyroid Disease became anaplastic thyroid cancer, one of the rarest cancers, which resists treatment," she said.
"He is the most loving and caring person I have ever known besides my father. Sometimes life just isn't fair. But we have such a great love story. He is the love of my life and I will do everything in my power to heal and care for him," she added.
At this point, Jill says that she and her husband are "hoping for a miracle."
Even though she isn't able to be there to help with the planning, Jill is planning on still hosting her 5th Annual Luxury Luncheon to raise money for thyroid cancer this weekend. Her hope is that Bobby will be able to attend the event.0comments
"On Saturday, we want to show him how much we love him by raising a lot of money for the International Thyroid Oncology Group, which is looking for cutting-edge treatments for advanced thyroid cancer."
Celebs expecting to attend the fundraiser include Atlanta's Cynthia Bailey, Miami's Marysol Patton and RHONY's Dorinda Medley, Luann D'Agostino and Tinsley Mortimer, as well as Kardashian pals Jonathan Cheban and Simon Huck, KC from KC and the Sunshine Band, and Bachelor in Paradise's Vinny Ventiera.