The former editor of Rupert Murdoch's now-defunct Sunday newspaper spoke of her difficulties becoming a mother during her "roller-coaster" first marriage, and her affair with Andy Coulson, her former deputy, who is standing trial alongside her.
Giving evidence for a second day in the trial at the Old Bailey court in London, Brooks talked about royal stings and the huge deals for exclusives with celebrities such as football icon David Beckham.
Brooks edited Britain's biggest-selling newspaper between 2000 and 2003, before running its daily sister title The Sun until 2009.
The 45-year-old appeared close to tears and asked for a break as she began talking about her fertility treatment, which was halted by the flurry of work around the 2003 invasion of Iraq.
"It was a tough year for us. Basically, life was put on hold for Iraq," she said of her marriage with TV actor Ross Kemp.
Brooks divorced Kemp in 2009 and later that year married her second husband, Charlie Brooks -- also a co-defendant -- with whom she has a two-year-old daughter born via a surrogate mother.
Brooks admitted to having had periods of "physical intimacy" with Coulson in 1998, from 2003 to 2005 and finally in 2006.
Coulson, her News of the World deputy, succeeded her as its editor and later became Prime Minister David Cameron's media chief.
"My personal life was a bit of a car crash for many years," Brooks told the court.
"It's probably very easy to blame work but the hours were very long and hard and you got thrown together in an industry like that. It was wrong and it shouldn't have happened but things did."
The court has seen an emotional letter from her to Coulson, written in February 2004, which police found on her computer.