INCREDIBLY ashamed over my first interview.

I had my very first interview today at a company that my brother works at, and I was literally only given this opportunity because he referred me to HR. Anyways, it went so fucking bad that I was only

I had my very first interview today at a company that my brother works at, and I was literally only given this opportunity because he referred me to HR. Anyways, it went so fucking bad that I was only asked two questions. I thought I was prepared, but I completely froze up when she asked me about myself. I had no idea what to tell her exactly because the question is so vague. She then asked me about what made me interested in the position, and even though I answered more coherently, I sounded stupid. The tour they mentioned in the email? Completely skipped. My brother thinks it was cut short because they're super busy over there but I think that's just copium. I was expecting it to be a little awkward but this interview was so abhorrent that I was in tears as soon as I walked out of that building. Edit: Well, somehow I was hired and I start next week. Thank you all for the advice and kind words, I’ll try not to fuck up as bad at future interviews.