Where does it come from? Why has it got so much power? It has so much power over you because it was born from a core belief that was created when you were too small to cope and certain events and personalities have re-enforced it throughout your life. Somehow, you came to believe that you didn't matter as much as something or someone else, that you were unimportant to those who should have been there for you. The only tools you have to deal with that pain, are the tools that you had when the core belief was first created. For most people that began before the age of five. It could have been something a simple as being left at kindy or something truly life changing like divorce or the loss of a parent. It may have been perception or reality that created it - the child's mind knows no different.
How do you change it? Questions. It will not stand up to the questioning of a rational adult mind. When you question it, you will come to realise that whatever happened to you when you were 2 or 4 or whenever these beliefs first appeared in your mind, that it cannot possibly be your fault and that you didn't deserve it. For the lucky ones, they may even come to understand that it was a child's perception of events and it was never true.
For the not so lucky it might help you to understand this.....the reasons that our loved ones weren't there for us or did us wrong, are human reasons. A vicious or selfish person is reacting to everything with their own behaviour patterns that were created from their own core beliefs. They have never stopped to think why they do what they do - even when they know what they've done is wrong. It has not even occurred to them that there are different ways to deal with the curve balls life throws at us - or if it has, they've been this way for so long, they're more afraid of changing than death itself. Sometimes we just get caught in someone else's dance.
A link with ALOTTA knowledge :) http://www.depression.org.nz/content/home
Understand that you cannot stop being when you change and that change is our very nature - with every breath, heartbeat & thought, we are changing. Know that your future is not black as night, that finding out who you really are is not an unknown journey. You were always you, from the very beginning. Your job now is to uncover YOU and rediscover YOU and explore what the adult YOU loves to do.
So......your new tool is: "I'm an adult now - I can be whatever way I want to be and when I leave my old beliefs behind, I will finally have a chance to be me". The sun is rising before me, its a brand new day and I'm off on an adventure to rediscover ME."