When actors get pigeonholed, that's their own doing to a large degree. Because if you do something that people like, obviously they're going to ask you to do it again. It's up to you to say no. If you're that insecure about working, you'll probably do what you're known to do.
“When you're reading, you're not where you are; you're in the book. By the same token, I can write anywhere.”