Its hard work..to change or atleast to find that person deep inside of you. I think just knowing that a change is needed is the first step.

From what you have written you know what has caused you to perceive things the way you do and understand the psychology behind your behaviour so maybe now it is a matter of recognising those moments of insecurity and stamping it out then and there IYGWIM. Like for instance you are argueing with someone because deep down you are fearful they are going to abandon you- so in this moments you really need to talk yourself through it like "i'm feeling this way because ........ but now I know I am loved and care for by others"...IYGWIM?

I agree with Kelly- affirmations are amazing little things and keep you conscious of what your thinking and feeling...

I gave my mum a Lousie Hay book last year as she has been suffering depression for years...she said it was the best thing she could have got- maybe have look into this and see if its something you can get into?

GL and