You are a good coach and you have coached yourself through some very fantastic accomplishments so far, both in and out of the water. Trust that. Trust you.
There will be obstacles; there should be. Take those obstacles and embrace the power they hold. Learn and move on. This is exactly what life is about. You have the ability to achieve so much, if you just allow it to be so.
That feeling that overcomes you during a race, that one that you fear because you can't control it; you actually can. YOU are the one that created that energy in the first place. You just have to learn how to use it during your race. In a week you will have the opportunity to try it out. You are lucky.
Feel it all, take it all in. Believe in yourself and enjoy this journey.