"Denial is powerful. Until I really knew what I was dealing with, I realized, 'This isn't just a muscle thing,'" Hamill said during a Good Morning America appearance with professional partner Tristan MacManus.
The 1976 Olympic gold medal winning figure skater was apparently diagnosed with a cyst on her spine.
"It's radiating down my leg and my foot, and I have no stability in my ankle. I can't put my toes back," she noted, adding that revealing the news of her departure to her fans and fellow contestants during Tuesday night's live results show was very difficult.
"I was kind of trying to keep it together because I didn't want to be a blithering idiot."
Hamill also said that last night probably won't be the last Dancing with the Stars viewers will see her and she may even return to compete in another season.
"I would love to come back... I'm going to be sitting there rooting everybody on, so I'll be here definitely," Hamill insisted.
An emotional Hamill and MacManus announced their decision to remove themselves from the competition at the end of last night's broadcast, bringing many people to tears.
"I have taken the advice of my spine surgeon and I need to withdraw from the competition. I have an injury that could be irreparable and nerve damage, and it would be completely unfair for me to stay in this and have any of these people go home," Hamill explained.