#!/usr/bin/perl
use strict;
use warnings;

my $text = do {
    local $/; #slurp
    <DATA>;
};

my @comments = $text =~ /(?<====Comments===).*?(?==|$)/gs;
my @additional = $text =~ /(?<==Aditional Notes=).*?(?==|$)/gs;
1;
__DATA__
===Comments===

This webpage contains information bla bla bla

=Section 2=

Some more text here.

===Comments===

Some other comments here.

=Another section=

=Aditional Notes=

More notes here.