I believe that is the excellent fic,
"When The World Finds Out by C.C. Aiken.
I read it too and had nightmares about Clark's secret exposed. On the other hand, it does end on a hopeful note.
SPOILERS:
Things I like: It turns out Perry has known the secret for years.
The kids.
C.C.'s set-up of a trap that even Superman can't escape.
END SPOILERS
There is also
a version posted on Annesplace.net, the nfic Archive. You will need the password to get in.
