The left side manifestation of our Vishuddhi is in the form of self respect. When our self-esteem is low, it is difficult to respect ourselves and give ourselves the credit we deserve. Thus we can easily feel guilty for our mistakes, carrying them with us and allowing them to further erode our self-esteem.
To avoid guilt and unblock this chakra it is important to face our mistakes, to accept the lessons we still need to learn, and to move on. When we have low self-esteem we can also easily fall into relationships which are in fact destructive, rather than filling us with a sense of self respect. The pure brother-sister relationship instead raises our sense of self-respect which protects us from entering into detrimental relationships.