WordPress homepage is blank after changing site URLs

I’ve moved my site from a test website on my own domain to my client’s website, and tried to change the links accordingly. At first everything was working fine, but when I tried to move WordPress to its own directory, I messed up by putting a “/” at the end of each URL. I wasn’t able to access the dashboard, the site was showing errors, etc.

Long story short, I backpedaled and I’ve tried again. I can thankfully access the dashboard now, but the homepage is blank. The source code shows that it’s loading the host’s default “this site is under construction” page rather than the index.php I’ve put in the root directory.

I’ve tried deactivating all plugins, switching themes, changing the values in the wp_options table, and hard-wiring new URLs in the wp-config.php and functions.php file. But nothing seems to work.

I’ve never run into a problem like this before when migrating sites manually. I would have used Duplicator, but the client host’s server doesn’t seem to be compatible with it.

The site is www.poconoschiropractor.com.

EDIT: Here are the contents of the .htaccess file in the root directory (also want to note that the redirect isn’t working even though it worked before):

# 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

RewriteEngine On
RewriteCond %{HTTP_HOST} ^www.drwyckoffchiro.com$ [NC]
RewriteRule ^(.*)$ http://drwyckoffchiro.com/$1 [R=301,L]