Speaking on the final day of the trial before closing statements, the actress said: "Perhaps it's easy to forget, but I am a human being."
Mr Depp, 58, is suing Ms Heard, 36, over an article she wrote in which she said she was the victim of abuse.
He has repeatedly denied her claims.
Over more than a month of testimony, jurors have been presented with starkly different versions of incidents that took place throughout the couple's troubled two years together.
Both actors accuse the other of being the aggressor in the relationship and have called witnesses to testify on their behalf. A number of the witnesses called by Mr Depp's team have directly contradicted Ms Heard's claims.
"I know how many people will come out and say whatever for him," Ms Heard said in court on Thursday. "That's his power. That's why I wrote the op-ed. I was speaking to that phenomenon."
Ms Heard's testimony on Wednesday also led to a tense exchange with Camille Vasquez - Mr Depp's now viral lawyer - over an image of spilled wine. It is one of several pictures Ms Heard has presented, allegedly from a huge fight the couple had in 2016 which ended with Mr Depp assaulting her.
At one point, Ms Heard turned to jurors and claimed the photos had been redacted or edited by Mr Depp's lawyers to benefit her ex-husband's case.
"I'd appreciate if you wouldn't be making arguments to the jury," Ms Vasquez said sternly. "I didn't ask you about anything."
Throughout her testimony, Ms Heard repeatedly denied accusations she was lying or misled jurors during the trial.
Her testimony, she added, had led to "hundreds" of death threats on a daily basis and forced her to "relive the trauma" of her marriage.
"This is horrible... this is humiliating for any human being to go through and perhaps it's easy to forget, but I am a human being," she said. "As I stand here today, I can't have a career. I can't even have people associate with me because of the threats and the attacks that they will have to endure."
Mr Depp is suing Ms Heard for $50m (£40m) for a 2018 comment article she wrote in the Washington Post in which she said she was the victim of abuse.
While he wasn't named, his attorneys have said it "incalculably" damaged his career. She has countersued him for $100m.
Closing arguments will begin on Friday, followed by jury deliberations.