I just checked the site and everything seems to be working to me so assuming you've already got it fixed up. If not, you may need to clear your cache and cookies.
Or did you have a different design before or something? I'm assuming if you customized a lot of the files within your theme and then updated then the custom changes would have been overwritten.
It's usually best to take a backup of your files and database before making any type of update to WordPress.
The files can be backed up before hand by using and FTP client like Filezilla (free at http://www.filezilla-project.org) and the database can be backed up by using a database administration tool called phpmyadmin or something similar to it.
However, in your case if you're still encountering an issue I'm assuming you don't have a backup so you may want to try checking with your web host to see if they have any backups in place that they could provide to you.