Well, as someone who failed my first mod one on a silly mistake despite doing it fine in practice, and hated the pressure of the tests... Firstly, it's normal. Lots of people feel that pressure. If I had to retake them tomorrow I'd feel the same. I would say you have passed the hard one, or the one that's easiest to fail already!
So just ride it as best you can. Take your time, remember the observation/mirror/signal/look/position routine or however you were taught it. And only ride to whats realistically in front of you... don't worry about dual carriageways if you're in town and a 20 limit! Keep yourself and your attention in the moment. Take your time, don't rush, and you'll be fine.
I passed mine in pissing october rain when the examiners radios were broken so we had to keep stopping to give instructions in batches of 3... I was concentrating so hard on riding properly I completed buggered up the directions from about half way through... he had to beep me and shove his indicator on at one point as I wasn't going to pull over where he thought I should.
Utterly embarrasing and I thought I'd failed, but I did every turn and roundabout by the book, observed, waited as some pretty silly stuff happened in front of me on a roundabout.
MOST importantly, and I think this helped me pass... I spotted that his pannier had fallen open in the first 500 yards so told him at the first stop; so he knew I was looking in my mirrors properly.
Oh, and if you fuck everything up, just say "sorry I must have misheard you".
