(NEW YORK) -- Terrence Woods, Sr. has left his son's room at his Maryland home largely untouched for over four years. He can't bring himself to change it since his son, Terrence Woods, Jr., went missing on Oct. 5, 2018.
With no new information about his whereabouts, and many unanswered questions, every day is a struggle that presents more sleepless nights, he told ABC News.
"It's almost like a cancer. It's killing from inside out but you have to deal with it," he said. "My son's bedroom was the same way it was the day I took him to the airport. Me and my son have the same name. So I can't escape it at all."
Woods, Jr., 27 at the time, went missing while filming in Idaho County, Idaho, for the Discovery show Gold Rush with production company Raw TV, according to other crew members.
His father said he was told that witnesses saw him run suddenly down the side of a cliff into a wooded area inside Nez Perce National Forest in Orogrande, Idaho, after saying he needed to use the bathroom. Years later, no trace of him has been found.
After Woods Jr. went missing, a search and rescue operation by the Idaho County Sheriff's Office took place.
Following his disappearance, authorities utilized helicopters, canines and ground teams in its search, but were unable to locate Woods Jr., the sheriff's office said.
"No leads were obtained from the previous seven days of searching, and no signs of Mr. Woods have been located in the search area or the expanded search area," the sheriff's office said in a statement in October 2018.
According to Woods Sr., the circumstances surrounding his son's disappearance do not seem clear cut. According to crew members, Woods Jr. had an anxiety attack earlier that morning and was "acting strange" in the moments leading up to him allegedly running off, Woods Sr. told ABC News.
A spokesperson for the Idaho County Sheriff's Office told ABC News the case is still open and active, and that investigation will continue pending new leads.
Woods, Sr. told ABC News that the past four years have weighed heavily on him, but he's not done searching for his son.
"It's nights where I try to go to sleep and I can't sleep. It's nights that I'm afraid to go to sleep, so I don't hear him, I don't see him," he said. "With death, you have two things: closure and healing. I have nothing."
As he continues to do his best to cope with his son's absence, reminded by his photos and artwork around the house he grew up in, Woods Sr. said he hopes he'll one day have answers that clear up the mystery behind the disappearance.
He said he hopes people remember Woods Jr. as a "happy-go-lucky" person who deserves to be looked for.
"He just wanted to be who he is, you know. And he just wanted people to accept him for who he is. And I say who he is because he is still here," he said. "Don't take life for granted. It could be pulled right from under your feet."