"I've never really been this scared for my life," Ethan Zohn says in his latest video diary. Sitting in a hospital room, the Survivor winner taped the piece as he was about to start his first new round of chemotherapy – since learning that the first three months of chemo aimed at knocking out his Hodgkin's lymphoma wasn't enough.
"The cancer is back ... and it's trying to destroy me," Zohn says. "But I'm not going to let that happen."
Zohn describes in detail the gravity of the new treatment he's about to endure – starting with more chemotherapy, followed by a harvesting of his healthy stem cells; a series of radiation treatments twice a day, everyday, for two weeks; and finally a full stem-cell transplant.
Of the final leg of what he describes as the "triathlon" of treatment, he explains, "They lock me up in the hospital for 30 days and they pretty much destroy my body, get all the blood cells out of my body, and then they'll reintroduce my stem cells and build me back up to perfect health."
The process will require he be kept in full isolation until his immune system is rebuilt.
"For all you Seinfeld fans out there, I will officially be 'The Bubble Boy'!" Zohn jokes.
Striving to remain as upbeat as possible, Zohn says, "I'm gonna need to hijack all your thoughts, your prayers and well-wishes for the next seven to 12 months."
"I get so much comfort knowing that we're all fighting this together," Zohn says, directing his thoughts to PEOPLE.com viewers. "Please everyone, stay positive, and keep a good sense of humor. And that's about it," he adds, before putting a protective mask on his face to begin his first new round of chemotherapy.
For more on Ethan's ongoing treatment, keep coming back to PEOPLE.com