I have Rheumatoid Arthritis. I know you will probably hear a lot of people with a disease like this say "I don't want to be defined by my disease", or "I am not my disease".
This is simply not possible for me, however I do not choose to wallow in self pity either. My life has been turned upside down, I simply cannot escape that fact.
I had started stunt-training the year before my Triggering Event. So that is something that will never happen anymore.
There are days when I can't brush my teeth or hair, where I can't walk due to inflammation in my hips and ribs.
And I do not have the same energy I had to be able to do any of the things I can still do.
Do I focus on this too much?
Sometimes I do. Sometimes feelings have been held in check for long I do have a mini meltdown.
Sometimes though I have to admit that I cannot do something, that people have to take that into account when working with me.
Those times I tend to feel rather guilty as I know I look perfectly normal on the outside and seem to be all right and indeed have little pain.
Those are the times I have to remember that I am telling people to take it easy to prevent real problems happening. It's a precaution, not a cop out.

So yes, the pain and fears do have an impact on my life. I am dealing with it and hopefully educate some people along the way.
Do not assume that someone who is younger than you who is doing something to annoy you (walking slowly, sitting in a seat on the bus for the disabled or elderly) is simply being a pain in the butt for the sake of it. Some of us who share the same space as you are dealing with things that you cannot see.

Also pain tends to make people not able to think clearly. If we make no sense, please remember that.