Folder rename has locked me out

Hi

Hope someone can help. I’ve renamed my wordpress folder (to match a new add-on domain). I’ve been experimenting all morning, and must have changed the root in my general settings, because it all went pear-shaped and havingI renamed the folder back, now I have a site with content, but no CSS: when viewing the source I can see that the stylesheets are being called from the new folder name, and I cannot log in via wp-admin in either folder.

Does anyone know how I can log in?

http://www.shakespeareonstage.co.uk/

Thanks in advance, and Fingers crossed…

Jez