There’s a few things you can do:
Find out what type of learner you are - visual, audio or kinaesthetic then base your recall round that.
Use visualisations and mnemonic's to help memorising and recall - such as memory palaces, loci and Roman room methods also acronyms etc.
Active recall just means to scribble out what you’ve read previously. It strengthens the memory path ways. Visualisation and memory palaces work the same way - it builds pathways to the memory.
Watch you tube videos on the subjects. Read books such as how to ace your alevels and GCSEs.
Go on you tube and find a teacher that you understand. I found Mr Bruff for English and GCSEMathsTutor really helped me.
Make learning your job, set out your work hours and include off time doing sports as it not only relaxes you, but helps build memory pathways.
Study in 20 minutes chunks with 5 minute breaks in between.
Memorise 7 bit chunks at at time, the short term memory forgets after 9 bits.
Study before you sleep as that will help
Eat a well balanced diet with omega oils (oily fish), berries, broccoli and lots of green veg.
Get your study space organised. Do your revision somewhere as close to the exam setting as you can - table, chair, put an exam background noise (you tube have exam noise videos)
Also using smells and taste - sniff peppermint or eat a sweet when revising then use that in the exam will help recall.
Other things to try are mind maps- blurting them on a page to recall everything you know. Also sticky notes round the house to read can help.
Self belief is a must. Imagine you’ve already past at the 9 and do the work to get there. Literally live the subject during the day. Use spare time to revise - ie waiting for the bus. Get friends and family to quiz you or teach it to friends/ family, pets or even toys.
Good luck.