Here's an exert.
Some people have the terror of facing a terminal diagnosis,
while others have a reasonable chance of living a long time with/despite their
disease (not always a happy thought). Some people, such as myself, feel really
truly lousy on even the best of days. Until I got sick in this way, I never
understood how severely ill a person could be most or all of the time for years
on end. I understood loss of function, and even chronic pain, but the idea of
feeling sick all of the time (without being terminally ill) never seemed to hit
my radar screen.
The rest is also worth reading.