The best advice I ever received was before I even worked on my first film. It was "Just don't take anything personally, and you'll be fine" A Rock Concert Producer coaxed me to pursue my interests in the performing arts industry.
Its one thing to be in an Art Department in your local on a small show where everyone is from town, and perhaps the Art Director is a bully because they are threatened to keep their place in such a tight community of talented artists and designers, all vying for key positions. Those shows are easy to quit. You know its not personal, its competitive. If you can handle the shit, great; its not like they want to get rid of you. If life's too short for you, and the days are too long, whats the point in staying on a show? It becomes a personal choice for you.
Sometimes though, its not so crystal clear. I was working on a big feature; all of the personell above the line were from NY; I diddn't know any of them, nor they I. I was the 3rd and bottom Set Designer on the crew. The Assistant Art Director had hired the local crew: she was local. It was off to a good start.
But very apparently, the NY Art Director had a problem with me. I was drafting a barn. He insisted my math was wrong. It turned into 2 weeks of hell. He had me draft every intersection full size. He argued with me over math, which diddn't make sense. Math that the construction coordinator backed; then I wasn't allowed to communicate with the construction coordinator....
I quit after drafting over 80 plates in 2 weeks; none of which were ever to be issued to construction under my initials. The moment I quit, he came up to me, a completely different person. He was nice and kind! There was an impromptu byebye tea party in the Art Dept. 15 minutes later I heard I had been replaced.
The Art Director wanted to bring up his Set Designer from NY. And in order to do that he had to prove to the Union that he could not find adequate help here locally. This is the Film Biz. Never forget it.
Just don't take anything personally, and you'll be just fine.