Deep blue, just start by saying "you have no power over me" and keep saying it. The more you do the more it will come to be true. A friend of mine once said to me that it's very important to say things the way you want them to be, it helps to rewire the brain. While we think negative thoughts it reinforces that belief system.
So we need to change the belief system and saying things the way we want them to be starts the process.
When I first started my journey to mental well being I used to stand in front of the mirror and say positive affirmations to myself. It was one of the hardest things I have ever done. At first I could not even look at myself, now I can look myself in the eye and say "you are a person of great worth and value" and mean it.