Silver Lining
The good thing about NATS is that they allow you to apply 3 times.
The thing I would be concerned about if I were you is running this race again next year [or even sooner- I dunno, ya probably COULD!].
Stage 1: get a few books that teach you to use your brain a little better in these tests/spend some dosh on those practice tests...even use shl if you want!
Spend your free time in aviation, you learn so much by just being in the scene. Even try working in aviation if you can.
But most importantly use your time productively with a focus of that final hurdle in stage 3, where they will ask you 'what you have done for a year?'...
...think of it this way- you have a year to get things right, not just for interviews but for college too.