But the good news: Hamill, 54, is cancer-free, and has been so for two years.
"It's out of my system," the 1976 Innsbruck, Austria, gold-medalist, who's currently training for several upcoming performances, said at Monday's 25th Great Sports Legends Dinner to benefit the Buoniconti Fund to Cure Paralysis, held at Manhattan's Waldorf-Astoria. "I'm here and so far, so good. I'm not feeling great but I'm better."
During the early part of her treatment, Hamill, who was cared for at Baltimore's Johns Hopkins Kimmel Cancer Center, participated in clinical trials for different medications. She now takes Tomaxafen, which is used to reduce the risk of recurrence but produces side effects that leave Hamill "achy."
"I don't have a lot of energy," she says. "I get really tired. Even when I'm not skating I get tired."
Still, for the first time since her diagnosis, Hamill skated last summer on Nantucket, where she runs a skating camp.
Balancing ActHamill's diagnosis came on the heels of a crippling depression she discussed with PEOPLE in 2007.
"It's a balance," Hamill, remarkably fit looking and blue eyes as sparkling as ever, said Monday, of battling both depression and cancer. "It's going well, but some of the medications I was on before, I have had to work and try to get the right balance, but so far it's good."
As she notes, "There is no magic pill. It's exercise, eat well. You have to do a little of this, a little of that. There is no magic wand."
When it came to support during her cancer bout, Hamill leaned heavily on her family, her friends and her relatively new husband – her third: "It's wonderful, I got it right this time, three times the charm," she says, keeping his name and identity out of public view.
Now getting back on the ice to train, Hamill "feels hopeful." Having recently participated in this month's Stand Up to Cancer televent, Hamill was surrounded by doctors and researchers who share her optimism.
"I think [cancer] is complex and complicated, and it takes a lot of money and time," Hamill says. "But they are hopeful."