Nerves, wrong answers and a very distracted interview

I can't stop sweating, I'm digging my nails into my palms, biting my lip, I can feel that my shoulders are stiff and I'm very upright, my breathing's shallow and I keep jiggling my foot around.
No, I'm not waiting for some sort of horrific surgery, nor am I about to give a momentous speech.
The above description, in fact, is my exact feelings before my first ever job interview, approximately an hour and a half ago. I know what you are probably thinking 'oh it's normal to get nervous before interviews', but seeing as I had no prior experience, this goes above and beyond normal nerves. Yes, I reluctantly admit, I was shitting it. And in retrospect, I can see why.
What are you supposed to say?
'What are your hobbies and interests?' Well, do you want the truth? I think my favourite thing to do is find pictures of attractive men and post them on my Tumblr blog. Oh, that doesn't count as a hobby? Oh, he'll think I'm a complete freak if I say that? Okay, how about watching endless episodes of the Hills? Bitching? No? Okay, I'll go with 'err, I do a bit of acting' (epic lie, I haven't acted in almost a year, unless you count lying to wrangle my way out of awkward situations).
'Where do you like to shop?' Again, the truth will get me nowhere. I can't tell if my interviewer will look disgusted or simply alarmed if I proclaim 'VINTAGE!', so I squirm in my seat whilst thinking of a plausible answer. If I go with standard high street haunts, he might think I'm boring. If I'm outlandish and reference Brick Lane or Portobello Road, he might think I'm some wannabe hipster. I settle with 'err... Topshop, H&M, River Island...' Another epic lie, I have neither the money nor the figure for Topshop and hate buying from H&M because the world and her best friend have the exact same things as you.
When my interview finally ceases, I'm left with another mind-blowing dilemma; how to part ways? Do I give a brisk but firm handshake and tell him I hope to hear from him soon? Or tell him it was nice to meet him? Another lie, meeting him has left me in a heightened state of stress and emotional turmoil. Yet again, I blunder, grunting some remark about expecting a phone call and actually stumbling out of the room (I like to think I made an impact).

Alas, I didn't get the job, so my summer will be budgeted until then. I sincerely hope anyone reading can learn from my fatal mistakes. Have your answers prepared in your head, try as hard as you can not to panic and be friendly.
And for your own good, I hope you don't have an attractive interviewer, as I did. It's so distracting.