I deeply believe that it is possible to change your patterns of behavior, it's just difficult work because you have to in effect "re-wire" your brain. And because so many of these patterns play out on a non-verbal level and are unconscious, it takes being in a relationship with someone who can help you see what you're doing and not aware of. I'm reading a really good book on Attachment right now called, appropriately enough

There's some quotes from the book I'll post later when I have the time about this subject, but I didn't want to let it go to long without answering.
You are not broken, or sullied. There may possibly be some scars, but scars are a sign of healing. That which does not kill us, only makes us stronger. And postpones the inevitable.

AG