Thanks for the replies. No job in particular just any job and I haven't got the right figure for a suit either. I might just get a jacket/blazer type thing. I have done mock interviews at the job centre but that was a complete fail.
I usually wear a smart pair of trousers, shirt and a jacket for interviews, with normal work shoes (for me black mary janes) but I've always worked in a fairly business casual type environment, so that's appropriate.
I remember reading that one way of getting interview dress right is to check out your potential new workplace, see what most people are wearing and then dress slightly more smartly than that. If your new workplace has everyone wearing suits then you need the equivalent, if they are all wearing jeans then smart casual is fine (ie the next step up from jeans). Seemed a fairly good rule of thumb to me.
If you are really uncomfortable talking about yourself and looking at people then you need to practice. Can you ask friends/family to do a couple of mock interviews with you just to get you more comfortable?
What sort of job are you looking for? I certainly don't think you need to put on any kind of "girly" outfit if that's not your thing. If it's for the sort of work where you need to be smart, and you have the figure for it (i.e. not a giant arse like I have) would a suit look good?