PHP - Set a Variable within while loop - php

Question

I'm currently trying to set a variable within a while loop equal to different values of an array. I have my select statement setup so that it pulls the information successfully and can be displayed by echoing the relevant classes. However, if I try to set the rows equal to a variable on the second pass it doesn't run and completes the while loop.
$username = "xxx";
$password = "xxx";
$hostname = "xxx";
$database = "xx";
$dbhandle = mysqli_connect($hostname, $username, $password, $database) or die("Unable to connect to MySQL");
$conn = new mysqli($hostname, $username, $password, $database);
$date = "1996-03-12 12:03:00";
$selectcmd = "SELECT starttime, endtime, partner, worklist, serviceloss, servicereference, siteaddress, ticketref FROM work WHERE starttime='$date'";
if ($conn->connect_error) {
die("Connection Failed: " . $conn->connect_error);
}
$result = $conn->query($selectcmd);
if ($result->num_rows > 0) {
while($row = $result->fetch_assoc()) {
$body = $row["starttime"].$row["endtime"];
require "mail.php";
}
} else {
echo "No Mail To Send";
}
$conn->close();
mail.php is the PHPMailer function and sends emails fine.
I know the issue is that I'm trying to set a variable within the while loop. However, I'm not sure how to overcome this. I've attempted to unset the body at the end of the while loop.
mail.php for those who asked:
use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\Exception;
require 'PHPMailer/src/PHPMailer.php';
require 'PHPMailer/src/SMTP.php';
require 'PHPMailer/src/Exception.php';
$mail = new PHPMailer();
try {
$mail->isSMTP();
$mail->Host = 'localhost';
$mail->SMTPAuth = false;
$mail->Username = 'user#example.com';
$mail->Password = 'secret';
$mail->Port = 25;
$mail->setFrom('test#test.com', 'test');
$mail->addAddress('joe#example.net');
$date = "today";
$mail->isHTML(true);
$mail->Subject = 'Important Notification';
$mail->Body = $body;
$mail->AltBody = 'This is the body in plain text for non-HTML mail clients';
$mail->send();
die();
} catch (Exception $e) {
die();
}

Answer 1

My issue was as #PatrickQ advised.
The die() function was causing the script to stop running altogether. I removed this from mail.php and then moved the require 'mail.php' to outside the while loop. I then added the $mail->send(); function to the while loop.
Everything is as I wish :)