Basically, I can access everything just fine using 127.0.0.1, but if I use my external IP (123.123.123.123), I get page not found.

My router is port forwarding HTTP port 80 to port 8080 on my servers internal IP address. In other words: (Application: HTTP | Start: 80 | End: 8080 | Protocol: Both | IP Address 192.168.0.101 | Enable [YES]) I know it's forwarding properly, because when I stop port forwarding, I can access my router page by using my external IP.

My virtual hosts file is:

NameVirtualHost *:80
    <VirtualHost *:80>
    DocumentRoot /opt/lampstack-5.3.16-0/apps/wordpress
    ServerName example.com
    ServerAlias www.example.com
</VirtualHost>

and my httpd.conf file is:

Listen 80
Servername localhost:80
DocumentRoot "/opt/lampstack-5.3.16-0/apache2/htdocs
<Directory />
    Options FollowSymLinks
    AllowOverride None
    Order deny, allow
    deny from all
</Directory>
<Directory "/opt/lampstack-5.3.16-0/apache2/htdocs">
    Options FollowSymLinks
    AllowOverride None
    Order allow, deny
    allow from all
</Directory>