[PHP] Insert mysql depuis textarea

Voici le code que j'ai finalement fait :
<?php
session_start();
if(isset($_SESSION['connexion_admin']) && $_SESSION['connexion_admin'] == '1') {
if(sizeof($_POST) > 0) {
require_once('config.php');
$conn = mysql_connect($host, $user, $mdp);
mysql_select_db($bdd, $conn);
$textarea = $_POST['insert'];
$bad = array ("\r\n","\r");
$textarea = str_replace ($bad,"\n",$textarea);

$textarea_cuted = explode ("\n",$textarea);
$tx_c = count($textarea_cuted);
for ($i=0;$i<$tx_c;$i++) {
mysql_query("INSERT INTO federal (id_enquete, fede) VALUES ('".$_SESSION['id']."', '".$textarea_cuted[$i]."');");
}
header('Location: fede.php');
}
}
else {
header('Location: index.php');
exit();
}
?>

Bonjour, voici ce sque j'ai fais, mais iil y a quand même une erreur :

<?php 
	session_start();
	
	if(sizeof($_POST) > 0) {
	require_once('config.php');
	$conn = mysql_connect($host, $user, $mdp);
	mysql_select_db($bdd, $conn);
	$txt = nl2br($_POST['insert']);
	$recherche = array('<br>', '<br />');
	$remplace = array ("'); INSERT INTO federal (id_enquete, fede) VALUES ('".$_SESSION['id'].", '", "'); INSERT INTO federal (id_enquete, fede) VALUES ('".$_SESSION['id'].", '");
	$txt = str_replace($recherche, $remplace, $txt) ;
	$sql = 'INSERT INTO federal (id_enquete, fede) VALUES (\''.$_SESSION['id'].', \''.$txt.'\');';
	echo $sql, '<br>';
	$query = mysql_query($sql) or die(mysql_error());	
}
?>