The singer paid tribute to her long-term partner Eddie Rothe, who died aged 67 after being diagnosed with lung cancer, on ITV’s Loose Women.
McDonald, 58, reflected on how “horrendous” the last six months have been for her but said her “heart goes out” to everyone who has struggled recently.
Speaking on the daytime TV show for the first time in two years, on which she was a fan favourite presenter from 2004 to 2014, she emotionally recalled the time she had with her partner.
She said: “Thirteen years of absolute bliss and that’s how I’m getting through it.
“I’m not thinking of the last six months because it was horrendous.
“I don’t want to feel sad for the rest of my life, because that wasn’t Ed.
“Ed was beholden, he was smiley, he was beautiful.
“I’ve got to do the first interview and I couldn’t be with better people here.
“It’s been tough, but there’s so many of us out there who have been through this, and my heart goes out to you all because it’s been a tough 18 months or so many of us.”
The interview began with a collage of video clips from McDonald’s time on the show and a timeline of the couple’s relationship.
McDonald and Rothe, best-known for being part of 1960s band The Searchers, first dated as teenagers but later drifted apart.
The couple rekindled their romance 27 years later after a chance meeting at the ITV studios in 2008 when Rothe was performing on This Morning and a set make-up artist convinced McDonald to reconnect with him after the show. They got engaged later that year.
McDonald said she is now trying to focus on the time they spent together, adding: “I’m not good at being sad. I’m not good at this. I’m not good at crying.
“So every day when I wake up and get that thud, like someone’s just hit me, I think are you going to go down the dark path, where you’ve been for the last year, or are you going to be grateful for everything you’ve got in your life, and grateful for the time that you had with him and remember him how I want to remember him.”
She also explained that due to coronavirus restrictions, Rothe was unable to receive care or have family and friends visit and so McDonald was given a crash course in nursing by a district nurse so she could look after him at home.
“At first I thought, ‘How on earth am I going to do that? I don’t know how to do this’,” she said.
“But then you get a strength when you’re nursing your loved one, and it really is a privilege.
“I learned how to do it and I changed all the dressings and I cared for him and I nursed him and I’m glad I did.”
McDonald said she is looking towards the future now, with a new TV series planned in which she will explore her home county of Yorkshire, and she will also do another travel show in the Caribbean.
She will also sing at the Royal Variety Performance and has a Christmas show lined up in Leeds on December 19.