The theme file header.php (or possibly header-raw.php) seems to have been corrupted.
Did you edit that file according to some instructions from some plugin?
(Note what the comments say: DO NOT EDIT THIS FILE – it seems to have been edited!)
Do you have some plugin that is fiddling with the <head> section?
If you need to change the header.php file, you should NEVER do it in the theme, but rather in a child theme.
Otherwise, you site has been hacked, and the hack has attacked the header.php file.