Hi Catherine - I, and other seasoned professionals, find ourselves in the same predicament. On one hand, you're a hard worker who appreciates the difference between a job and a dream, yet who also knows the value you can bring when you're motivated. On the other hand, you're finding yourself questioning your path and the impact of the path you're taking. It's expected that we will all question ourselves - our choices and our impact on the world - many times throughout our lives.
My advice to you is that you leverage your resources to help you make these tough decision. If I've learned anything in my years, it's that we all tend to exaggerate obstacles in our minds, and we have to trust those around us and leverage our resources to most effectively tackle them. In your case, I suggest you take the necessary time to focus on determining what you think your career should be. Keep in mind that you need to be practical (consider pros/cons, pay, day-to-day demands/expectations, alignment with your values/goals) and flexible (understand that your perception and life circumstances will change as you grow) in your decision-making. Then, once you make this determination, find ways to network with professionals in that field, and get their feedback (e.g., being in the field, do they see that X job on a resumé has helped people get that job; what courses/experience do they suggest). There's no better way to achieve a goal than to put a face to that goal and to have the experts help you get there.
You are not alone - in your existential struggles, or in making life-defining decisions.