In two new video diaries, the Survivor star shares the ups and downs of his battle with cancer

Ethan Zohn is now halfway through his three-month chemotherapy treatment for Hodgkin’s Lymphoma. In two new video diaries, filmed at his home in Manhattan, the now-bald Survivor: Africa winner shows viewers the ups and downs of his struggle.

In one video (above), the perpetually upbeat Zohn, 35, shares from among the mounds of supportive letters and numerous gifts sent by fans since he went public with his cancer diagnosis in May.

“The fan support has been awesome,” says Zohn, standing in his kitchen with girlfriend Jenna Morasca, 28, (the winner of Survivor: The Amazon), showing off the loot that includes sweatshirts, cases of SmartWater and toys aimed at keeping him busy during chemo treatments.

In a second intimate video, filmed at 4:53 a.m. on a sleepless night after his third biweekly chemo session, a surprisingly somber Zohn admits his fight against cancer hasn’t been easy. “Three months ago I was playing soccer, training for a marathon,” he says. “Now, I’m bald, skinny, can’t sleep at night, tired, nauseous.”

Still, even in the wee hours of the morning, Zohn tries to remain upbeat. “The only way to get through this is to remain positive,” Zohn says. While he has certainly wrestled with the question, “Why me?” he seems to have found his answer: “I’ve come to the conclusion that things happen for a reason, and maybe I was put on this earth to help others and educate others.”

As he heads into the final six weeks of chemotherapy treatment, which is expected to be followed by radiation, he adds, “I see the light at the end of the tunnel. I’m gonna use this to change the world, man. You know?”

Already, Zohn has been asked to serve as an ambassador for Stand Up To Cancer, the charity founded by CBS News anchor Katie Couric. He has also been asked to speak at events for Lance Armstrong’s Livestrong foundation.

Check back on every Thursday for more of Ethan Zohn’s video diaries.