主页面重定向自己，.htaccess错误

Question

so i have wordpress installed on website. Today i've worked with .htaccess file, and after all main page is redirecting on himself (f.e. mysite.com/mysite.com), so i get 404 error page. Have no idea what is going on, because hosting's team has made back-up and nothing has changed.

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L] 
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
</IfModule>
# END WordPress

Thank you!