I echo PP’s advice to choose a simpler piece and play it perfectly well, with stylistic understanding and appropriate use of dynamics and expressive techniques. You only need to do a Grade 5 piece well for top marks.
Composition - ensure you meet the brief and start early with many revisions! Ensure there is a clear structure, and that attention has been paid to ALL musical elements. Basic things such as ensuring you stay within vocal/instrumental ranges, you use appropriate stylistic devices, and the brief is met is all you need. Look at previous mark schemes to get ideas.
Listening - know the set works inside out and also how they represent their wider style. Be able to describe each musical element of each set work. Listen to at least one other piece in that article and practise comparing and contrasting them. Ask the music teacher to evaluate your answers.
Practise short rhythm and melodic dictation. Do aural work identifying cadences and recognising major/minor keys; simple/compound time signatures. Ideally be able to tell the difference between Baroque and modern pitch.
Remember the composition is less about ‘expression’ and more about meeting the criteria of the brief /mark scheme.
Make regular revision notes on the set works that are revisited as other new works are introduced so they keep ‘fresh’ in your mind.
And practise performing musically, not just technically!