Mysql affiche toute ma page php via ma requet

Bonjour,

j'ai un textarea qui est relié a ma base de donné lorsque je fai appel a la valeur du textarea sur le site il affiche dans un bloc toute la page html compilé
j'aimerai connaitre comment arreté cela
si vous avez besoin du code il est là
<?php
//-----------------------------------------------------------------debut du php-----------------------------------------------------------------------------------------------------------------
$mytext= isset($_POST['mytext']);
if (isset ($_POST['mytext'])){
try{
$pdo_options[PDO::ATTR_ERRMODE] = PDO::ERRMODE_EXCEPTION;
$bdd = new PDO('mysql:host=localhost;dbname=sbdb', 'root', '',$pdo_options);
//$bdd = $bdd->exec("INSERT INTO mynew(date) VALUES(())
$req = $bdd->prepare('INSERT INTO mynew (publication,mydate) VALUES(?,now())');
$req->execute(array ($_POST['mytext']));


$selection = $bdd->query('SELECT publication,mydate FROM mynew WHERE id > 2 LIMIT 0,1 ');
while ($donnees = $selection->fetch())
{



?>



<span class="gethide" style="display:block;height:120px;width:610px;margin-left:330px;margin-top:20px;padding-left:15px;padding-top:10px;">
<?php
echo nl2br (htmlspecialchars($donnees['publication'])) , $donnees['mydate'] ,'<br/>' ,'<br/>';
?><!--form commentaire -->
<form action="home.php" method="POST">
<textarea cols="50" rows="1" name="comment" class="comment">commenter...</textarea><br/>
<input type="submit" class="second" name="secondt" style="background-color:white; border-radius:5px;border:1px ridge grey;" value="commenter"/>
<?php
?>
<span/>
</form>

<!--fin FORM COMMENTAIRE-->
<?php
}

$selection->closeCursor();
}
catch(exCeption $e)
{
die('Erreur : '.$e->getMessage());
}
}

?>
</span>
</form>
<?php

?>
<?php
try {
$pdo_options[PDO::ATTR_ERRMODE] = PDO::ERRMODE_EXCEPTION;
$bddr = new PDO('mysql:host=localhost;dbname=sbdb', 'root', '',$pdo_options);
$selectionr = $bddr->query('SELECT publication,mydate FROM mynew WHERE id = 6 LIMIT 0,1 ');
while ($donnees = $selectionr->fetch())
{

?>
<span class="gethide" style="display:block;height:120px;width:610px;margin-left:330px;margin-top:20px;padding-left:15px;padding-top:10px;">
<!--<textarea cols="50" rows="1" name="comment" class="comment">commenter...<textarea/> -->
<?php

echo nl2br(htmlspecialchars($donnees['publication'])),'<br/>',$donnees['mydate'], '<br/>' ,'<br/>';
?>
<form action="home.php" method="POST">
<textarea cols="50" rows="1" name="comment" class="comment" >commenter...</textarea><br/>
<input type="submit" class="second" name="second" style="background-color:white; border-radius:5px;border:1px ridge grey;" value="commenter"/>
</form>

<?php
?>
<?php
}
$selectionr->closeCursor();

}
catch(exCeption $e)
{
die('Erreur : '.$e->getMessage());
}
?>
<?php?>