Only show sub-nav when in category page/post?

Here is my current code, it list all the category as page navigation and then post under each category as sub nav items.

But how can I make it only show sub nav when i’m viewing that category page/post?

<ul id="menu-navigation" class="menu">
			<?php // get all the categories from the database
			$cats = get_categories();
				// loop through the categries
				foreach ($cats as $cat) {
					// setup the category ID
					$cat_id = $cat->term_id;
					// Make a header for the cateogry
					echo "<li><a href=\".$get_site_url./".strtolower($cat->name)."\">".$cat->name."</a>";
					// create a custom wordpress query
					$catposts = new WP_Query( array( 'category__in' => array($cat_id), 'posts_per_page' => 10) );
					// start the wordpress loop!
					if ( $catposts->have_posts() ) : ?>
						<ul>
						<?php while( $catposts->have_posts() ) : $catposts->the_post(); ?>
						<?php // create our link now that the post is setup ?>
						<li><a href="<?php the_permalink();?>"><?php echo $catposts->current_post+1; ?></a></li>
						<?php endwhile; ?>
						</ul></li>
					<?php endif; wp_reset_postdata(); // done our wordpress loop. Will start again for each category ?>
				<?php } // done the foreach statement ?>
				<li><a href="<?php bloginfo('url'); ?>/contact">Contact</a></li>
			</ul>