It's hard. It's very, very hard. Especially since I got put on 12-hour shifts. Yes, that means I get 3 days off one week, and 4 the next, but since I generally spend the first of those days in something approaching a coma with occasional bouts of semi-consciousness, the extra time off doesn't help a lot. I'd rather be on 8-hour shifts with the ability to attend a class after work ...
I think what does help is that I've had sleep and other health issues all my life, and I've always just ... fought through them. I could outstubborn a mule when I'm fighting for something I want, and I really, really want to be able to change careers. I hate what I'm doing now. The new career may not be everything I hope for, but it should at last be intellectually stimulating. A half-trained monkey could do my current job most of the time--and some of the people I work with are almost that intelligent.
To find the best career for you, the first thing you should consider is what you enjoy doing. Do you enjoy helping people? Teaching? Talking on the phone? Writing? Programming? Making things? Designing things? Make a list, and put it in order from the things you like most to the things you like less, but could still be happy doing. Then, consider what career paths might let you do one or more of those things you like, and make another list. Cross-referencing them can help.
Once you have the list of career paths, consider the types of jobs in those paths and how they'll fill your needs. ("Computer Science" is a career path. "Programmer" is a job on that path. Or, conversely, "Programming" could be a career path with "game programmer," "database programmer," and other things as jobs.) Again, cross-referencing it can be very helpful.
Once you have that list, consider the circumstances you'll experience in the jobs on your list, and what effect they'll have on the EDS. Does being intellectually stimulated help you fight the fatigue/EDS? Look at the more intellectually challenging jobs, the ones where you have to figure things out--that's what I'm doing with going into programming, as one example. Another is making various types of repairs, whether on vehicles or, say, plumbing: you have to figure out what's wrong and how to fix it, then do the work. Would it be better for you to be up and moving? Look at jobs that don't involve sitting at a desk for hours at a time. That could be anything from retail to nursing. Does it help you to be surrounded by people? Look for a job that can give you that. Look at combinations of factors. If talking on the phone and constantly meeting new people is good for you, but sitting at a desk for hours isn't, it might be best to avoid working as a receptionist, but being a hostess or waitress at a restaurant might be right up your alley.
As an example of what I mean by "cross-referencing" these lists:
Things I like Careers Jobs Notes
Journalism Reporter Dealing with people all the time: bad!
Teaching English teacher Dealing with students all the time: bad!
Programming Programmer (various) Intellectual stimulation, creating new things, less human
Networking Network engineer Intellectual stimulation, less human interaction: good!
Creating known things: eh.
Support Help desk Dealing with people all the time: bad!
Astrophysics Astrophysicist A lot of intellectual stimulation, less human interaction:
good! Not many jobs: bad.
Teaching College professor Dealing with people all the time: bad!
Jewelry Making/selling jewelry Creating new things: good! Dealing with people/sales: bad.
Small carpentry Making/selling objects Creating new things: good! Dealing with people/sales: bad.
(boxes, shelves, tables, etc.)
ETA: That should be a little easier to read, I hope ...