I finally went to HR about my bully of a manager, and wow, what a waste of time. It went exactly how you'd guess. I laid out everything, and they just nodded along like they'd heard it all before. Turns out my manager had already gotten to them first with his side of the story. I got the whole "we'll look into it" speech, and then nothing. A week later, my schedule suddenly got worse and a project I'd been promised went to someone else. Nobody said it was related, but come on.
Lesson learned: stay away from HR.