Hey, in addition to physics and maths tutor you can do the combined science papers as well as the triple one's on the AQA website. Most schools have access to exampro so try asking your teacher to make you a pack for the topics you want to focus on. I did triple at GCSE and got all 9's and finished year 13 with A*s in biology and chemistry. The main difference between students that get top grades and those at grade 5/6 is that they are able to connect different topics together and have a better understanding of why things work the way they do.
Once you do exam questions go through them and see why it is you are losing marks. Is it because:
-you weren't able to recall the information correctly (if this is the case you just need to revise more and keep coming back to areas where your memory is weak)
- you weren't able to apply your knowledge to the question (there are only so many types of questions they can ask within the specification so just read through the mark scheme vigilantly and do loads of practise until your exam technique improves, it doesn't really matter if you redo the same questions)
-you have an issue with maths (again practise)
-you are unable to answer the werid practical questions that don't really have anything to do with biology (try and understand the definition of the words associated with this side of science e.g. validity, accuracy, being precise. Keep a bank of answers from the mark scheme that you can go back to before exams because you can often answer the same thing for different practicals)
- timing (this tends to be less of an issue once you are more confident in your ability to recall information. In the exam skim through the test paper to get an idea of how long it is and which topics come up, don't spend too long on a question if you are really struggling with it).
I have a revision pack that was written from the specification on my Etsy store if you are looking for additional questions that focusing on improving active recall. Another method of revision that works really well is teaching the content to someone as you can judge how confident you are with the material. I know it can be hard to find someone to test 24/7 so I have a digestion map route that you can preview for free on my Etsy store. If you just scribble down relevant answers to the different sections it should mimic teaching .
Please feel free to ask me anymore questions and not just about science.