The actress says she believes that she wouldn’t have survived if their marriage had continued.
Amber Heard feared her ex-husband Johnny Depp would accidentally kill her during an alleged assault on their honeymoon, a US court has heard.
Testifying in a defamation case Mr Depp has brought against her, Ms Heard, 36, painted a picture of the actor as an abuser plagued by drug addiction, jealousy and self-harm.
Mr Depp is suing Ms Heard for $50m (£40m) over an article in which she claimed she was the victim of domestic violence.
He has repeatedly denied any abuse.
The high profile case in Virginia has resumed for a fifth week after a pause, before which Mr Depp had told his side of the story and Ms Heard had begun some of her testimony.
In court on Monday, Ms Heard tearfully told jurors that she believed she’d likely “not survive” if she had remained married to Mr Depp, 58.
“I was so scared that it was going to end really badly for me,” she said. “I really didn’t want to leave him. I loved him so much.”
Ms Heard has accused Mr Depp of repeated instances of physical abuse. On Monday, she alleged that he attacked her while aboard the Orient Express train in Asia after their February 2015 wedding, claiming that he struck her and held her by the neck while in their sleeper compartment.
“He was squeezing my neck against the railway car for what felt like a very long time,” she said.
She said she recalled thinking he could “kill me”.
“I remember being scared that he wouldn’t mean to do it,” she said.
In another instance, Ms Heard described a “week of hell” after Mr Depp allegedly became jealous after she was offered a role with James Franco. She claimed he punched her and threw her into furniture.
Cross-examination from Mr Depp’s attorneys is expected to begin later on Monday.
While Ms Heard said that the marriage was “at times, very loving”, it deteriorated over time to a point in which tension and violence became “almost normal”. They divorced in 2017, after two years.
During their increasingly frequent arguments, Ms Heard claimed that Mr Depp would frequently self-harm.
“In fights he often would cut his arms or hold his knife to his chest or draw blood, superficially at first,” she said. “He also put cigarettes out on himself.”
In his own testimony earlier in the trial, Mr Depp said that he never struck Ms Heard and told jurors that she had a “need” for conflict and violence.
On Monday, jurors heard a number of audio clips of the former couple arguing. In one clip – which went viral ahead of the trial – Ms Heard can be heard saying she hit Mr Depp.
“I was hitting you. I was not punching you,” she can be heard saying. “You’re not punched.”
According to Ms Heard, she sometimes “reactively” hit Mr Depp and claimed that she was referring to the “disparity” of their strength.
The defamation case against Ms Heard stems from a 2018 piece she wrote for the Washington Post in which she characterised herself as a victim of abuse. The piece did not name Mr Depp.
His attorneys, however, have said that the article “incalculably” damaged his reputation and career. She has countersued him for $100m.