That's wonderful that you are feeling peaceful, if we could bottle the ability to stay calm no matter what we are being hit with in the present moment. I guess that is what mindfullness is all about, staying centered in a storm. Focus on priorities and things in your control, let the rest go.
There are lots of great sites to help prep for an interview. Questions and that sort of thing. I would get the interviewer talking by asking how long they been there, what do they like about it and copy their body language.
How are you doing today?