Have you done any changes on htaccess file of WordPress Website hosted on Digitalocean and not able to connect even with FTP client like Filezilla or Cyberduck etc ?
If you raise a support ticket with Digitalocean, their team most probably sends some information links with no clue at all to start from where, I myself have faced this kind of situation and found 100% working solution that can bring your website up as it was before. Here are the easy steps to be followed :
Step 1 Connect your site with Putty (if using windows) OR Terminal (if using Mac OS)
Step 2 Look for .htaccess files in your root web directory (/var/www for apache), and in any folder you’re trying to access. Since .htaccess files are hidden (aka dot files), you’ll need to use the command “ls -a” to see it.
Step 3 Open the file with a text editor “nano .htaccess” from the www directory, revert the changes or delete the lines that could possibly creating the error.
Step 4 Done, check you site’s 500 Internal error would have gone.