The 79-year-old actor was forced to put his wife of 56 years into an assisted care facility near the home they shared in Santa Monica, California.
He tells TV Guide magazine, "It wasn't easy, but I couldn't handle it anymore.
"It's a nice place and I see her every day, but she's losing herself, which is hard to handle for her. And us.
"You learn humility fast and how to cope with things you never thought you'd have to."
