Yep, I figured as much. Luckily it's booked in @ RSTuning on Monday. I will be driving very gingerly! It sounded terrible on Friday on the way home, just hope it hasn't affected the discs yet.If it's grinding it sounds like you're braking on the backing plates which is likely to mean you have no brakes at all, and are screwing your discs too.
I'd recommend the next time you drive it, you take it straight to somewhere where they can make your car safe again.