Wow, you leave us heartbroken for Clark and what he's lost here! I hope he's really going where I think he is...
Anyway, since I just read this story for the second time and kind of remembered what kind of mood awaited me, I was immediately reminded of the song
"Mad World" by Gary Jules (from the Donnie Darko OST -- yes, I've been thinking in songs recently and still am). And reading the story set to the song, it was outright scary!
You captured that sense of disorientation and loss well. Again and again, Clark discovers just how lonely he is...

"I am Clark Kent. I need to be Clark. I'd go crazy if I'd have to be Superman all the time."
"Creativity is the residue of time wasted." (Albert Einstein)
"The future is there ... looking back at us. Trying to make sense of the fiction we will have become. And from where they are, the past behind us will look nothing at all like the past we imagine behind us now. ..."
-- ("Pattern Recognition", William Gibson)