I failed my first driving test, although it went entirely my fault. I was emerging onto a two lane roundabout and a car already on the roundabout changed lanes without indicating and had to brake. Bearing in mind this roundabout has 5 exits, it's important that you indicate where you're going. Either way, I was able to get back in about 5 weeks later and passed with only 3 minors.
Also, remember that you only really start learning how to drive once you pass your test and you're driving full time.
Also not to freak anyone out but even as a confident driver, travelling to and from work 4 days a week (via motorways), I still managed to total my first car due to poor road conditions. With my second car, I may be slightly more cautious but sometimes being overly cautious can be more dangerous (i.e. doing 25 in a 40 zone, doing 40 on a motorway when there's nothing wrong with your car and it's national speed limit).
Drive to the best of your ability and practice lots (go up and down the motorway by a few junctions to get a feel for it) - disclaimer: I passed before they let learners on the motorway. But also don't get fazed by idiots who just want to go fast, let them go and focus on your driving and the cars immediately around you.
As my driving instructor said to me: as long as you're a safe driver, it doesn't matter what's going on around you.
But also as my mum pointed out: I trust you, I just don't trust the other drivers