Clues you should start looking for another job...
Your fixed nature means that it could take you a while before you find the career path that's just right for you, but once you do you'll stick to it like glue throughout your working life. And that may or may not be a good thing.
"Fixed" indicates persistence and self-reliance, yes, but it can also mean stubborn. Make sure you can recognize when it's time to let go and move on to a better opportunity.
It isn't that you cling to the comfortable so much as you find it hard to admit that your choice may not have been perfect! If you're unhappy and don't see room for improvement, start searching.