How to insert google forms spreadsheet data to wordpress database?

I have searched google and implemented this code but it gives
Warning: DOMDocument::loadXML(): Opening and ending tag mismatch: link line 2 and head in Entity, line: 94 in /home/etplpm/public_html/netsamningar/wp-content/themes/thestory/template-login.php on line 36.
I have changed Url and key according to my document but could not find any appropriate solution.

   $key = "...key...";

   $url = "https://docs.google.com/spreadsheets/d/...key.../pubhtml";

   $ch = curl_init();

   // set URL and other appropriate options
   curl_setopt($ch, CURLOPT_URL, $url);
   curl_setopt($ch, CURLOPT_HEADER, 0);
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);

  // grab URL and pass it to the browser
  $google_sheet = curl_exec($ch);

  // close cURL resource, and free up system resources
   curl_close($ch);

   $doc = new DOMDocument();
   $doc->loadXML($google_sheet); 

   $nodes = $doc->getElementsByTagName("cell");

   if($nodes->length > 0)
   {
       foreach($nodes as $node)
      {
           // 2nd row is the email row.
           if ($node->getAttribute("row") == 2)
          {
               if (eregi("^[.+_a-z0-9-]+@[a-z0-9-]+(.[a-z0-9-]+)*(.[a-z]{2,6})$", $node->nodeValue) ) 
               {
                     mail($node->nodeValue, "Mail Subject", "Mail Message.", "From: email@yourdomain.com");
              }

           }
       }
   }