Not OP, but if you're curious in attaining a *legitimate* diagnosis in something, collect and write down all of the symptoms that you exhibit and all of the ones you dont and to what degree. Then look into common differential diagnoses and collect and write down all of the symptoms that you exhibit and all the ones you dont and to what degree. Then do research into the clinical side of those disorders. That means reading what actual, individual psychiatrists (not psychologists or therapists) say they see in people presenting with tbose disorders. Then go see an LCSW or therapist (not a psychologist), especially one who specializes in your issue, with all of this info and see what they think about it. If they don't click, try someone else or move up the ladder to a psychiatrist (seriously, not a psychologist). If your problems are categorizable, you'll get diagnosed with something even if it's not what you want.
If you want to fake an illness to get diagnosed with, look up the symptoms and act them out the best you can. Best case scenario, they sus out that you're lying and try to address the underlying reasons for it.