Chill out. Relax. Listen to your school.
Bristol have great feedback but it is possible to get feedback overload. Work through feedback a few times over until you a) understand the working behind the correct answer and b) can remember the correct answer even if you fail to understand the workings!
If you haven't failed a progress test so far I would imagine you're in good shape. I failed most progress tests (classic underachiever!) but still passed the real thing. What school are you at?
Put the hours in and reap the rewards.
Good luck,
VFE.