Hello Wandering Soul: It may be mostly a matter of improving your work area. Such things as having an ergonomically designed chair, having your computer correctly positioned (assuming you use one...), having the opportunity to get up & move about periodically, can go a long way toward helping you to be able to work more comfortably. It's not so much about improving you as it is correcting your work area. When your work area is ergonomically correct, you will just naturally maintain correct posture.
I obviously don't know anything about what you do, or who you work for. But your employer should be interested in helping you out with this. Work-related injuries cost employers big bucks. It would be to their advantage to do what is needed to ensure that you are able to perform your duties comfortably & without putting undue strain on your body. I wish you well...