I have mocks in four weeks and no idea what to do

I’m pretty overwhelmed by stress right now - so little time, and so much content to learn! What I’m really worried about is sciences. I basically need to learn everything, and I don’t have much feee time anyway, due to the ridiculous amount of homework we’re being set by unsympathetic teachers. I’m aiming for a nine, and I have the CGP revision guides and workbooks, but is copying them out really the most effective way to revise?

It looks as if Freesciencelessons, Primrose Kitten and Science with Hazel are the most widely used YouTube channels for this, but which is the best, and could I possibly get a top grade just by watching those videos?

All of them also offer revision guides and workbooks, but I’m not sure whether it’s worth buying them, bc I’ve already spent so much on all the CGP stuff! So please, what should I use, and what techniques should I use to revise, considering I have barely any time?

Any advice would be much appreciated, as I am basically dying over here (

Thank youu