The singer - who was engaged to the "Twilight" actor before their split in 2017 - has opened up on the "hurtful and ignorant" comments she received from some of his fans throughout their romance.
Speaking to Louis Theroux on his "Grounded" podcast, Twigs said, "People just called me the most hurtful and ignorant and horrible names on the planet."
"He was their white Prince Charming and they considered he should be with someone white and blonde."
The singer, real name Tahliah Debrett Barnett, admitted the trolls made her hate her own appearance, and that the bullying had a psychological impact.
"It's essentially bullying and it does affect you psychologically," she added.
Twigs also insisted while she would never "deny" her past - including her previous relationship with Robert - she is keen to point out that neither of them should be "defined by it."
"I'm not trying to deny my history, I just think it's important that I'm not defined by it, because he doesn't have to be defined by it," she sighed.
In the same interview, FKA Twigs also offered details of her alleged abusive relationship with Shia LaBeouf. She claimed the "Honey Boy" star banned her from making eye contact with any other men. "So then I'm looking down all the time, and that does a lot to someone's confidence," she said.
She also said he would "punish" her if he felt she didn't touch or kiss him enough during the day. The actor allegedly started an argument with her and made numerous unfair accusations against her to make her feel like "the worst person ever."