"I'm not a porn star. I'm not an animal," the woman, testifying under the pseudonym Jane to protect her privacy, wrote Combs on October 16, 2023, according to a text message she read aloud in court.
"It's loveless for me and nothing satisfies you and you always push me to do more and more."
The messages could bolster prosecutors' contention that Combs, 55, for two decades coerced women to take part in the sexual performances, sometimes known as "Freak Offs," against their will.
Combs is charged with using physical force and threatening to cut off financial support to get women to take part in the drug-fuelled, sometimes days-long performances in hotel rooms while he watched.
Combs, the founder of Bad Boy Records, has pleaded not guilty to charges of racketeering conspiracy and sex trafficking.
His lawyers have acknowledged that Combs was occasionally abusive in domestic relationships but say the women who took part in Freak Offs did so consensually.
Jane, the third alleged sex abuse victim of Combs to testify at his trial in Manhattan federal court, told jurors last week that she was "head over heels" for Combs at the outset of their relationship, which lasted from 2021 through 2024.
She testified that most of the time they spent together involved sex performances with male escorts in hotel rooms, even though she wanted to go on dates with just Combs.
She said Combs - whose net worth Forbes estimated at above $US1 billion ($A1.5 billion) in 2022 - threatened to stop paying her rent when she said she wanted to stop having sex with other men.
Combs' defence lawyers are due to cross-examine Jane later this week.
The trial is in its fifth week.
Combs could face life in prison if convicted on all counts.
Also known throughout his career as Puff Daddy and P Diddy, Combs turned artists like Notorious B.I.G. and Usher into stars, elevating hip-hop in US culture and becoming a billionaire in the process.
1800 RESPECT (1800 737 732)
National Sexual Abuse and Redress Support Service 1800 211 028
