The actress welcomed her second child on January 23, but started bleeding heavily afterwards to the point where her heart stopped for 40 seconds. She returned to the panel just 19 days later for auditions in Edinburgh.
Speaking to The Sun, Holden explained that she chose to rejoin Britain's Got Talent in order to restore some normality to the life of her six-year-old daughter Lexi.
"Going back to work when I did is how I deal with things," she said. "I always face life head on. I wanted to get back... So I did my hair no matter how I was feeling and I came down in the morning. I had to put breakfast on the table when I was feeling like a zombie.
"But it made me stronger and I was determined to get back to work as soon as I physically could... I face every disaster and crisis head on. I've never hidden away. Working is what I love and what I know."
Holden, who is married to record producer Chris Hughes, added that she had only been able to cope with the loss of their unborn child in February 2011 by throwing herself into work.
"Six weeks after losing our son I was rehearsing for Shrek [The Musical]. It gave me focus and fitness. Without that I would probably have gone down a much darker route," she explained.
"It's that attitude that has got me back to where I am now. It helped me get over what I've been through. Not just this but also the stillbirth and the miscarriage."
Holden has also said that she "couldn't face" having another child.