If your morning height is 5'9.5" I'd expect you to measure 5'8.75" or something like that at night which is closer to what people see you as, especially if you lift a lot like I think you do
Unless by morning height you meant mid morning and not out of bed. Than that's not that bad. You lose your morning height quickly
I lose about half an inch most of the times durimg the day, unless I lift very heavy that day when I lose 3/4 of an inch.
That said, I always wear 1 inch lifts, not only to appear taller but because they help with my stiff achilles tendons. So most people see me like 5.10+ and noone ever sees me shorther than 5.10. One time I told a 5.5-5.6 girl I am 5.9 to see her reaction and told me that she truly believe I was about 5.11.
For some reason, I see myself as shorter than other 5.9 guys although next to them I am even taller than they are due to my lifts.
However, other people perceive me at least as my real height with lifts (about 5.10). Maybe because I am big and they think I am at least 5.10 due to that.
Otherwise I believe I look shorter than a slim 5.9-10 guy due to my mass, as you said.