The couple ended their five-year romance in July, with reports claiming that their hectic work schedules caused the split.
Following the break-up, the former Pussycat Doll singer began filming the new ITV reality series and has admitted that she found it difficult to contain her emotions.
"It's been a tough year," the Daily Mail quotes Scherzinger as saying. "On the personal side it has been a hard year for me. I am not a robot and I wear my heart on my sleeve.
"Music touches me, so I think I've been a bit more emotional through the audition process this year because I was obviously going through some stuff internally."
The couple previously split temporarily during their relationship.