Was using WhatSize to look for hidden CD/DVD burn scratch files eating up space, as I'd read others have done. Burned a DVD, got rid of the image, and was still missing 5 GB. Found the only item of around that size - something in "Users," but neither user profile - instead ".<username>", or something similar. Put it in the Trash but did not delete, in case it contained anything important.

When I logged back in, my account had basically crashed. Cursor works but even Finder won't load. Logging in from another (non-admin account), I can't find any of the files on my HDD!! I know they're still there, because the space is still taken up...but how do I access the trash to pull whatever that was out, or to fix this???