"I love him very much and this is very hard to go through," Newton-John told Good Morning America in her first televised interview since the disappearance. "He has a young son so we still hold out hope that he will come back."
Newton-John, who was at a health retreat she owns in Australia when she learned of McDermott's disappearance (she returned to the U.S. at the end of July), told co-hosts of The View Monday that her initial reaction to hearing about McDermott was utter shock. "I was just kind of frozen. … But you have to move on. I didn't think I was going to sing again, but I am singing again."
She called her working-as-therapy approach "having to walk the walk. And I am walking the walk."
The Australian-born singer, 57, also told Entertainment Tonight, that the situation is "really, really painful for me, and really, really personal." As for promoting her new album, Stronger Than Before, Newton-John said: "I really thought of not doing it, but the album is about going through difficulty and getting through it. … I also know that Patrick would want me to do it because he believed in the cause and following through with your commitments. He was a very hardworking committed person, so I made the decision to do it."
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Newton-John, perhaps best known for the 1978 movie Grease, and McDermott, a cameraman, met in 1996 while filming a commercial, shortly after she was divorced from her husband of 11 years, Matt Lattanzi. They have been sporadically linked ever since, making their most recent public appearance at a black-tie ball in January.
Among the theories attached to the case is that McDermott might have faked his own death because of financial problems. "It appeared he was always short of money," Scott Gurican, who has lived across the street from McDermott's house in Van Nuys, Calif., for nine years, told PEOPLE. "But he didn't seem like someone who would bail out."
Monday Newton-John said: "It's very much a mystery and speculation has been rife and I choose not to buy into the speculation. This is such a personal thing for me and his family and we've chosen not to talk about it because it's an ongoing investigation."