The singer – who rose to fame with 1980s boy band Bros – has been starring in his own Las Vegas show for 11 years before signing up to the BBC dance contest, and admitted he needed to be pulled out of his reclusive lifestyle.
Goss, 53, confessed at Strictly a press conference: "I've been asked to do the show a few times. But this year, in an unhealthy way I was becoming reclusive in my world of doing shows, concerts and touring.
"I would then retreat too much, especially as it got into my eleventh year of my residency."
He added: "I felt myself going into a not very good place and it already feels better to have made the decision."
The When Will I Be Famous? singer lost his mother Carol to breast cancer in 2014 after moving her out to Los Angeles to care for her. He also cared for his stepfather Tony for four years after her death, while continuing to star in his residency at Caesar's Palace in Las Vegas.
Goss said: "I lost my mum and I steamed through my grief with my work. Because of that, I just missed London and said, 'I want to go home'.
"And a week or two after that Strictly called and it just felt like a sign. I could either go back to that reclusive place or I could do it and get out of my own way."
Since rehearsals began, the singer – whose twin brother Luke Goss remains in the US after forging a successful career as a Hollywood actor – is already starting to feel competitive.
He said: "I am bloody nervous though. I'm certainly not here to lose, I want to win."
Goss previously revealed he felt in peak physical condition for the dance show.
He said: "I’m eating everything that’s favourable to Spandex. I’ve got to make sure it’s alright, I’m excited."
The Bros star joins 14 other celebrities including Countryfile and former Blue Peter presenter Helen Skelton, The X Factor's Fleur East, Loose Woman Kaye Adams, Paralympic Ellie Simmonds and soap stars Kym Marsh and Will Mellor.
Strictly Come Dancing will return to BBC One with the launch show on 23 September and the first live show the day after on 24 September.
Watch: Who is Strictly's Matt Goss?