My blog is dead: php errors when attempting to view blog or log into wp-admin

…pulling my hair out.

I was working on playing with a new theme today for my blog at ThreadSpot.com. I downloaded the JStheme (site is very slow), a K2 type theme. Before installing, I thought I would update my WP to the latest version (hadn’t done this in a while). Accidentally, I clicked to install version 2.3 RC1 from the WP dashboard. I downloaded and updated my WP. After installing, I was working with different widgets and skins and attempting to tweak the look.

I then went to edit some posts, noticed the WYSIWYG editor was gone– just code view. I assumed this was because I had installed 2.3 RC1 instead of the older 2.2 I had running.

Foolishly, I assumed that just downloading WP 2.2.3 and uploading it to my server would resolve the problem, take me back to a stable version. This did not work, and now I receive errors when trying to view the blog or when trying to access the WP-admin.:
Fatal error: Cannot redeclare kubrick_head() (previously declared in /home/stylesle/public_html/threadspot/wp-content/themes/default/functions.php:11) in /home/stylesle/public_html/threadspot/wp-content/themes/default/functions.php on line 10

Any suggestions? Fortunately, I backed up my WP database before doing any of this…