Hello Moira,
Sorry to hear about your problem with the Admin. One of the best ways to get the admin working again would be to get into your database and revert the theme back to a default like twenty-thirteen.
You would need to be able to open your WordPress database, look at the wp-options table and then search for your current theme name by looking at the table entries. The table entries you’re looking for are labeled:
- template
- stylesheet
- current_theme
Look in your themes folder and make sure that one of the default themes are located there (ex: twenty-thirteen). Change the entry in the database to that theme name, then try running the site again and going into the administrator. (You can also review instructions here: How to change WordPress themes directly in the database)
If you continue to have problems, I would check:
- Check your .htaccess file (see here for the default .htaccess file for WordPress)
- Turn off all your plugins and make sure that the base files are in place.
Make sure to make a backup of your website before making any alterations to your files or file structures. Once you have a backup, you can try moving your files into a clean installation. Check out this post on how it can be done: Moving from an old WP install to a clean install
