Kids work really hard to get into a good high school
High School kids work really hard to get into a good college
College kids work really hard to get into a great first job
Young Adults working really hard to progress their career
Adults working hard and burning out because that is all they really know.
If you've always been an A student, and had a good career, its hard to change mentality and not put everything into your job. But if you're burning out you have to. I dont think its necessary to quit your current job. But you should consider not trying so hard. Just doing your hours, dont volunteer to do extra, and figure out what you enjoy that makes you happy. It could be enjoying nature, or making new friends, reading history, volunteering or doing a creative hobby.
It doesn't mean you can't have a great career. It could be just a quiet few months or years before charging in again, or maybe you're actually more productive not working all hours, or maybe you could change your whole path on life. The important thing is to realize that working really hard is not the only option.