A lot of good advice already, the only thing I can add is have a good chat with your school and the instructors. Many schools will have a pretty good idea of which examiner will turn up and may be able to steer you towards one that they know. In such a case, perhaps you can talk to others about their experiences with this examiner, see if you can get the details about when you'll need to do the planning sorted out in advance, etcetera. You'll still need to perform to the same minimum standard, but with two attempts under your belt and a bit of a heads up about what's coming, you've got the advantage of being prepared for everything.
Sounds like you've given yourself quite a challenge in training for a PPL with such a restricted schedule. You've done pretty well in getting to this point, but with all the restrictions in place, I'm not surprised that the final hurdle turned out to be a bit bigger than normal. I'm sure you'll get there though, you wouldn't have gotten this far if you were a real hopeless case.
