Can I bore you with another story?
A colleague of mine was burst out laughing when I described myself as "average." I
was hurt and I guess it showed because she suddenly stopped laughing and tried to explain that she thought I was "above average" whatever that meant. I was so puzzled by the experience that I excused myself to do some work and went back to my desk near tears.
Later, I realized what a compliment this was. Her perception of me was that I was special in some way that made me unique, different, "above" average and it made me view others that way.
As much as we share commonalities, we are original.
Repeat that. Make it your pre-interview mantra. You do have something special and unique to offer and if you can't see it right now it's because you're too close to the mirror. Step back and look at the whole picture, but not from a superficial viewpoint. This is a metaphor.
Text me as soon as the interview is over. I'll call you back so that we can commiserate, or celebrate.