trouble appending/combining two variables - html

Question

Here's my code, It's a forum, there are posts with dislike buttons,like buttons, and a text box for commenting with each individual post, check the screenshot below. I'm trying to put the $comments variable, which are the comments itself, at the end of $posts so it displays below the posts properly like the like buttons and comment box are displayed.
I'm trying to just get the comments displayed underneath the comment box. If I call displayComments(the function in $comments definition) in the for each loop then the comments get displayed separately from the posts I've tried combining the $comments at the end of $posts with this operator +, and I've tried making a new variable equal to the both of them. Here's the code(not the full file).
<?php
include("connect.php");
include("check.php");
include("Trying.php");
include("Comment.php");
if(isset($_POST['username'])){
if (isset($_POST['post'])) {
if ($_FILES['postimg']['size'] == 0)
{
$postbody = $_POST['postbody'];
$loggedInUserId = check::isLoggedIn();
if (strlen($postbody) > 160 || strlen($postbody) < 1)
{
die('Incorrect length!');
}
connect::query('INSERT INTO dry_posts VALUES (null, :postbody, NOW(),\'\',0,0)', array(':postbody'=>$postbody));
}
}
if (isset($_POST['comment'])) {
$postid = $_GET['postid'];
$commentbody = $_POST['commentbody'];
if (strlen($commentbody) > 160 || strlen($commentbody) < 1) {
die('Incorrect length!');
}
connect::query('INSERT INTO comments VALUES (null,:comment, NOW(), :postid)',array(':comment'=>$commentbody,':postid'=>$postid));
//}
}
$dbposts = connect::query('SELECT * FROM dry_posts ORDER BY id DESC');
$posts = "";
$comments = Comment::displayComments($p['id']);
foreach($dbposts as $p){
if (!connect::query('SELECT post_id FROM dry_likes WHERE post_id=:postid', array(':postid'=>$p['id']))) {
$posts .="<img src='".$p['postimg']."'>".htmlspecialchars($p['body'])."
<form action='try.php?postid=".$p['id']."' method='post'>
<input type='submit' name='like' value='Like'>
<span>".$p['likes']." likes</span>
<input type='submit' name='dislike' value='Dislike'>
<span>".$p['dislikes']." dislikes</span>
</form>
<hr /></br />
;
<form action='try.php?postid=".$p['id']."' method='post'>
<textarea name='commentbody' rows='3' cols='50'></textarea>
<input type='submit' name='comment' value='Comment'>
</form>
<hr /></br />
";
//Comment::displayComments($p['id']);
}
else{
$posts .="<img src='".$p['postimg']."'>".htmlspecialchars($p['body'])."
<form action='try.php?postid=".$p['id']."' method='post'>
<input type='submit' name='like' value='Like'>
<span>".$p['likes']." likes</span>
<input type='submit' name='dislike' value='Dislike'>
<span>".$p['dislikes']." dislikes</span>
</form>
<hr /></br />
<form action='try.php?postid=".$p['id']."' method='post'>
<textarea name='commentbody' rows='3' cols='50'></textarea>
<input type='submit' name='comment' value='Comment'>
</form>
<hr /></br />
";
//Comment::displayComments($p['id']);
}
}
?>
<form action='try.php' class = "forum" method="post" enctype="multipart/form-data">
<textarea name="postbody" rows="4" cols="60" class = "text"></textarea>
<br />Upload an image:
<input type="file" name="postimg">
<input type="submit" name="post" value="Post">
</form>
<div class="posts">
<?php echo $posts;
?>
</div>
Here's the function I'm calling in the $comments variable
public static function displayComments($postid)
{
$comments = connect::query('SELECT * FROM comments WHERE post_id=:postid',array(':postid'=>$postid));
foreach($comments as $comment)
{
echo $comment['comment']."<hr />";
}
}
I know this won't help a lot of people but I'm just not sure what to do, How do you suggest I get everything to display inline, should rearrange my code?