"I'm separated from my husband right now, which has been a very difficult thing to go through, but we have a lot of love for each other and we have this beautiful baby," Duff, 26, told Billboard.
Duff and Comrie have been photographed together multiple times after they decided to split.
Duff says she deals with the breakup in of the tracks of her upcoming album. "[There's a song] about my separation and my love for this person, that maybe we're not meant to be together, or maybe we are. It's very, very personal," she explained.
The singer's remarks come almost one week after she announced her return to music after signing with RCA Records. Duff released her debut single "Chasing The Sun" and its official video earlier this week.
The former Lizzie McGuire star explained that music came back into her life while she was pregnant with son Luca, 2.
"I was about to give birth, I was actually pregnant, and I had, like, two months to go -- I was a house walking around -- and I just started writing a lot out of nowhere," she said. "I don't know if it was because I was hormonal and emotional, but I started writing and I took it as a sign that I'm missing that part of my life."
Check out the singer's full interview for Billboard's Pop Shop Podcast below.