I'm four years out, and still get fatigued more than I used to before diagnosis. My stamina decrease, I think, really can't be solely accounted for by age.
It's the fear factor that may be interfering with this fatigue, though. I tend to get tired as a response to fear. As a result, since diagnosis, somewhat risky behaviors like skiing, rides at amusement parks, which never used to phase me, now fill me with trepidation, and I can respond with fatigue, as I said.
Other than this dramatic change in behavior response, I still think my fatigue level is up, generally. I also have some post-radiation pneumonia (chronic) that has lingered. I think oxygen intake probably has something to do with it.
Hope these factors have helped you think about how to talk to the doc. I've thought a lot about this one.
"Our greatest glory is not in never falling, but in rising every time we fall." -Confucius
Don't knock on Death's Door. Ring the bell and run. He hates that.