50 Cent SUED By Music Video Girl for Defamation -- He Got Me Blacklisted

50 Cent has ruined a video vixen's life -- getting her blacklisted in the business by calling her a "thirsty video bitch" in front of millions of people -- or so the woman claims ... and now she wants millions to call it even.

Sally Ferreira filed the defamation suit against Fiddy, claiming he FALSELY accused her last month of spreading rumors she was dating the rapper -- as well as leaking behind-the-scenes photos from his music video shoot.

50 posted the accusations on Instagram and Twitter (where he has a combined 9 million+ followers) including a call to blacklist the model, writing, "WARNING: Do not attempt to work with this thirsty video bitch."

For her part, Ferreira says she NEVER leaked the photos -- and insists she's openly been in a relationship with her fiance for 9 years.

Ferreira claims 50's Internet postings -- which have since been deleted -- not only ruined her blossoming modeling career ... they have subjected her to endless public ridicule and scorn. She says she's suffered extreme emotional distress as a result.