I made the fatal mistake of rename the usr directory.

I cannot run any commands due to the fact that ld.so.1 is in usr/lib/--and it doesn't exist

How can I recover my system?

There are a number of ways to fix this. It depends on which utilities are using the shared libs. Try the cat()
built in like this, perhaps:

cat >> /etc/ldconfig
/current/path/of/your/lib/dir
#or whatever the name of your ldconfig files is
#on your system.
^D^D (control D twice)

The command above will use cat to 'cat' a temporary
path and append it to the LDCONFIG file (your
system has it's filename, whatever for ldconfig.conf).

Then run the command ldconfig() (or similar) and
rebuild your LD table.

That is one possible fix. There are others, including
changing the environment variable (if you system uses them for LDPATH, etc.)

You can also just boot the system off a boot disk, mount the
filesystems and rename or relink. Then reboot.

Don't panic