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.
“You're successful if you can get one person to pick it up and put it on the turntable and go, Wow, thanks for writing that!”