do_shortcode close

Use get_field instead of the_field. That way you can assign it to a varilable.

$first_comment = get_field('first_content_block');
$second_comment = get_field('second_content_block');

echo do_shortcode("[vr_jsp] $first_comment, $second_comment [/vr_jsp]");

I haven’t tried it, but see if that works.