The interview with the 48-year-old Scot – a preview of which was shown on The Today Show – was aired on America's Got Talent on Wednesday evening and showed Susan addressing topics including her upcoming album, her stay at the Priory and her extraordinary rise to stardom.
"The impact was like a demolition ball. You know, and anyone who has that kind of impact finds it hard to get their heads around it," the West Lothian-born star told journalist Meredith Vieira of her thrust into the spotlight.
"Through the guidance of a great team, and they are very good, I was able to see that in perspective and really able to turn that around a little," she added.
Susan also revealed how her late mother Bridget – whom she spent a great deal of her adult life caring for – continued to inspire her to follow her dream. When asked what words her mother would have for her today, the talent show runner-up said: "Susan, keep going. Keep going, you're doing really well."
Speaking for the first time about her highly publicised stay in London's Priory Clinic, the singer said frankly: "Well when people get exhausted, they automatically have to have a rest. That was necessary at the time .I just needed a rest. I just needed to get away."
And going onto to discuss the audience's reaction when she walked on stage at the very first auditions for Britain's Got Talent, she smiled wryly and said: "Never judge a book by its cover."
Conversation naturally moved on to Susan's impending album, but the church volunteer – whose interview pushed President Obama's national address forward an hour – was keeping her cards close to her chest.
"I'm not going to give too many secrets away at the moment," she said. "It's something of a surprise."
Fans did get the chance to see a short video clip of Susan in the recording studio singing Ella Fitzgerald song Cry Me A River, which will feaure on her new record. It was also revealed this week that her first single from the album, which she hopes to release before the end of the year, will be a cover of Oscar-winning song, Moon River.