Finally got a resit today and passed with flying colours - both my landings were top-notch and everything else was pretty good too (had to resit the whole test) except for low flying, which was fairly mediocre (too much instrument flying) but still passable apparently. Onto CPL training now! Already got a cross country booked for Sunday.
Thanks for all the comments everyone - I do definitely take the first fail as a learning experience and feel that it's made me a better pilot on the whole.