Hi Jeremy,
The first thing I would try is contacting your hosting company, they often provide a service were they will restore old versions of your site. I think this would be the easiest solution if it's possible.
If that isn't an option you could try and manually recreate the site. First I would carry out a fresh install of CMS Builder on your server using the same credentials as you used on your old site, but use a new table prefix. Once the system is installed navigate to cmsAdmin/data/settings.dat.php and look for the line tablePrefix, and change it back to the table prefix you had before.
'tablePrefix' => 'old_prefix_',
This should link up your CMS to previous tables and data. Next you will have to manually recreate your sections using the same field names as before. If you have access to PHPMyAdmin on your server it might be easier to find the field names and section names you used before.
Let me know if you have any questions.
Thanks!
Greg
Greg Thomas
PHP Programmer - interactivetools.com