It is a reality that most people need to work to earn money. Without employment most people do not have sufficient means to survive. There is nothing surprising about this. At the same time a lot of people back themselves into a position where they need the job they are in, or at least that's what they believe.
Needing a job and needing this job is not the same thing.
Life is much too stressful if you are stuck in a job, even if it is a job that you like. Your livelihood is controlled by whims of decision makers that may not even know you. If an organization decides to stop doing what you do, there is a very real chance that you may no longer have a place in that organization.
It is important to be able to do something else. It may not pay as much, especially in the beginning but being able to move on your terms makes everything more tolerable.
Broad experience is very important. Taking two steps back and understanding the fundamentals of what needs to be done is very powerful. The industry specific knowledge is important but it can be learned quickly. Knowing how action A impacts outcome B is much more important.
However, the most important thing to know about any job is the common denominator of all organizations. It doesn't matter if it is a government organization, a charity, an educational facility, or a business. It does not matter if it is big or small. It doesn't matter what it is trying to do. All organizations are made up of people trying to accomplish goals. That's it.
Knowing this means that you can take what you know at one place, add in a bit of industry specific knowledge and be successful elsewhere. You can make the change. You can lead the way.
All of this to say if you want to be more comfortable, make sure you have a variety of experience. Make sure you can apply your skills to a multitude of situations. It may mean you need to take some courses to round out your knowledge. So do it.
I saw Lou Holtz speak. If you don't know who he is, he was the Head Football Coach at Notre Dame University and at the University of South Carolina. One of things he said is don't let others get in the way of your success. Just because someone else doesn't think you can be successful, don't let them win. It might be hard, do it anyway. You might not be ready, do it anyway. It might not be perfect, do it anyway. If they can't let you be successful, walk away and be successful elsewhere. Do it anyway. Have the options to walk away to and the courage to do it if the time comes.
Most pursuits you will either be successful or you will quit. Don't let the organization quit on you. If they can't handle it, move on and do it anyway. Set yourself up for success. You may not move on tomorrow but if you feel they are holding you back, you will move on someday.