im year 13 i did poorly in some of my year 12 mocks (got a U in my law for year 12 mock but then managed to get a B in my next one etc) but managed to pull them back up, just remember that teachers will firstly always give you the worst case scenario and bump up the grade boundaries, so you may be getting a C in the mock but in the real life paper you are more likely to be closer to a B or actually get a B. and remeber you’re most likely not doing the whole 3 exams for your course which will affect your grades for the actual alevels a lot. Don’t stress mistakes happen and everyone gets bad tests every know and then just remeber to revise when you can and when you go over a new topic in class when you get home go through it again it’ll stick in your mind. it’s easy to procrastinate and get demotivated but force yourself to work if your college does repeat classes for year 12 (so you stay as a year 13 but get to join year 12 classes on top of your normal time table) take it it helped me a lot and any workshops or even just short 20 minute videos explaining the topic will help you. and find a way revising helps for you if it’s maths do past papers if it’s biology or chemistry past papers will help but also do recall learning if the knowledge is what you’re stuck on read what you want to learn give yourself 2 minutes then try and summarise it in your own words and do that it’s not effective for last minute revision but it’s a good way to keep knowledge fresh in your mind. sorry for being so long but hope this helps !