I think it's far more important to be comfortable with what you are doing than to be 'right'
That said, I agree with the mighty Weeeeeksy, that you could do with being lower on the bike, in racer mode as it were.
The other really good bits of advice I have had are to relax, and to breathe. Sounds obvious doesn't it, but you'd be surprised!
I actually tell myself as I'm cornering to breathe, and when my forearms start to tighten up I literally let go of the handlebars!

With time it will feel more natural, I can't corner to save my life without hanging off now!

Oh yeah, you weren't going slow either! ;)

Thanks guys, your comments re being lower will be taken in, digested and hopefully acted upon next time out. Interesting that both you and weeksy noticed this cos the instructor sure didn't mention that one.