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.
“David wasn't thinking of being king when he was tending sheep; he was just doing what God sat before him.”
“Mankind is like dogs, not gods - as long as you don't get mad they'll bite you - but stay mad and you'll never be bitten. Dogs don't respect humility and sorrow.”