Insert sidebars between posts – how do I code this in my index.php?

I am using a Twenty Eleven Child Theme and I’m trying to insert sidebars (well, widget areas) between the posts showing on my home page. (My website if you think it’s helpful to have a look, although I don’t think it’s necessary?)

I have registered the sidebars in functions.php as follows

register_sidebar( array(
		'name' => __( 'Post widget 1', 'yourtheme' ),
		'id' => 'sidebar-7',
		'description' => __( 'Widget area between 1st and 2nd post', 'yourtheme' ),
		'before_widget' => '<aside id="%1$s" class="widget %2$s">',
		'after_widget' => "</aside>",
		'before_title' => '<h3 class="widget-title">',
		'after_title' => '</h3>',
	) );

There are two more (Post widget 2 and Post widget 3) which I made in the same way.

These work in that they are visible and functional in Appearance>Widgets.

Obviously however I need to tell index.php where to put my sidebars. I looked online and found a few ways to do it, they all say to insert some code here:

<?php while ( have_posts() ) : the_post(); ?>

					<?php get_template_part( 'content', get_post_format() ); ?>
				        <?php /* Insert here */ ?>	

				<?php endwhile; ?>

For each of the sidebars it should be something like

<?php if ( !function_exists('dynamic_sidebar') || !dynamic_sidebar('Post widget 1') ) : ?>
<?php endif;?>

…with the appropriate names filled in.

However, for some reason none of the things I found online actually specify (or specify correctly) which sidebar goes underneath which post. Whenever I got the sidebars to show up, they’d ALL show up underneath ALL posts. That’s not good, I just want the first sidebar underneath the first post, the second sidebar underneath the second post and so on.

I think what needs to happen is that I need to tell the while loop to only show Post widget 1 after post 1 etc. by having it do something different for each iteration, but I cannot figure out how (I’m not experienced with PHP, and everything I tried actually prevented the sidebars from showing up altogether, ha).

I don’t know if I’m thinking along the right lines there, but even if I am I can’t work out how to code it in PHP properly. Any help is much appreciated!