Look what they made her do! In a heartbreaking Tumblr post on June 30, a “sad and grossed out” Taylor Swift revealed her “worst nightmare” had come true: Justin Bieber’s manager, Scooter Braun, had paid $300 million to buy Big Machine Records, which includes the rights to her entire music catalog. “Essentially, my musical legacy is about to lie in the hands of someone who tried to dismantle it,” the singer, 29, wrote, referencing Scooter’s backing of Kim Kardashian and Kanye West in their infamous feud, and claiming she wasn’t given a fair opportunity to buy back her own work. “All I could think about was the incessant, manipulative bullying I’ve received at his hands for years.” Exhibit A? Justin’s 2016 Instagram post mocking her. But Scooter’s favorite client was…