I am bad at job interviews

As I mentioned in my previous post, my Achilles heel, if you will, is an inability to perform well in job interviews. I appreciate that we all have our strengths and weaknesses; a friend of mine is so poor at arithmetic that he once sold his house for what turned out to be a teabag, but my weakness is particularly debilitating.
Once, at an interview for the job of Junior Basket Weaver at the Wicker Institute, I became so flustered when the interviewer asked me if I would like a drink, that I shrieked for a full ten minutes. I just need to control my nerves.
Another problem is that I'm caught out easily. Once, an interviewer at the Cat Lover's Almanac asked me the question;

'If you were an animal, which animal would you be?'

To which I replied,

'Dogs, 'cause I fucking hate cats.'

I'm also rather accident-prone; at an interview in the Quality Assurance department at the House of VeryExpensive China, I fell out of a window.

I'm beginning to think that the 'lucky' tri-corner hat I wear to my interviews is not as good a talisman as the hobo who sold it to me had me believe.