Jotaro

He's lost more than he's ever gained. Especially with the shit he had to deal with when he was just 18

^Yeah and he has to internalize it all because he has to be macho. I bet he's secretly an alcoholic by the time of SO

Jonathan watched his dad die and his house burn down.

Jotaro watched all his friends die, including his mothers suffering and the death of his grandfather and gaining PTSD.

(Who knows what kind of suffering he faced during the years inbetween DIU, GW, and SO)