Why do you think you can help me change if I have not been able to do it alone?

First of all, a Coach can help you bring about a change, by giving you structure and holding you accountable.
A good Coach, can also help you see the situation from a different perspective, and come up with alternatives, you may not have considered on your own.
I have been through various challenges in my life, Through thorough research, and trial and error, I have been able to bring about immense changes, using simple and powerful tools. I also provide my clients with simple exercises, to overcome their fear, or other obstacles.
If during the first session, I feel that I cannot help you in your particular situation, I will be outright about it, and may also be in a position to recommend someone who can.