Adding data to an array in usermeta and displaying it in a loop

I have a front end post form where I take a file upload of an image. That image gets stored as a custom field which is easy enough to do. What I need to do though is store each unique image url for each user into an array in their usermeta. I want to do this so I can show them a list of those images they’ve already uploaded and give them the option of choosing one of those instead of uploading a new one.

So to elaborate I have a basic file upload choice in my form.

<input type="file" name="music_image" id="music_image"/>

Beneath this I need a check box select showing them the images of any others they have uploaded and somehow make it so if they choose a file they can’t select an image an vice versa. And then I need to add the uploaded file to an array as usermeta on form submit. Awful explanation but I think it makes sense.

Here is what I use to activate the form.

 <?php if( 'POST' == $_SERVER['REQUEST_METHOD'] && !empty( $_POST['action'] ) &&  $_POST['action'] == "new_post") {
if ( ! function_exists( 'wp_handle_upload' )) { 
            require_once(ABSPATH . "wp-admin" . '/includes/image.php');
            require_once(ABSPATH . "wp-admin" . '/includes/file.php');
            require_once(ABSPATH . "wp-admin" . '/includes/media.php');
}
$file=$_FILES;
// Do some minor form validation to make sure there is content
if (isset ($_POST['title'])) {
    $title =  $_POST['title'];
} else {
    echo 'Please enter a game  title';
}
if (isset ($_POST['description'])) {
    $description = $_POST['description'];
} else {
    echo 'Please enter the content';
}
$tags = $_POST['post_tags'];

// Add the content of the form to $post as an array
$new_post = array(
    'post_title'    => $title,
    'post_content'  => $description,
    'post_category' => array(11),
    'tags_input'    => array($tags),
    'post_status'   => 'publish',           // Choose: publish, preview, future, draft, etc.
    'post_type' => fod_music  // Use a custom post type if you want to
);
$overrides = array( 'test_form' => false);
$uploaded_music = wp_handle_upload( $file['music_file'], $overrides );
$uploaded_music_art = wp_handle_upload( $file['music_image'], $overrides ); 
//save the new post and return its ID
$pid = wp_insert_post($new_post);
update_post_meta($pid,'music_code',$uploaded_music['url']);
update_post_meta($pid,'music_art',$uploaded_music_art['url']);
wp_redirect( get_permalink($pid)); 
exit();

} 
do_action('wp_insert_post', 'wp_insert_post');
?>