301 Redirect Error Help

I’ve spent hours tonight trying to figure out why my website is getting an error https://www.21daystoaslimmeryou.com – it was working earlier, but now I cannot seem to fix this. I’m at my wits end and if anyone knows more than I do about this I certainly would be grateful for your expertise.

I’ve tried almost everything that has been recommended online, but still no resolve – here’s my .htaccess information. Hope you can help! Thank you!

# 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