I'm not sure when your GCSEs are, but mine start next week. Eek! First thing to do avoid panicking because that won't get you anywhere.
Research the syllabus for each of your exams because that will tell you exactly what you need to know for the exam.
At this point in time, you just have to accept that there's no way you're going to be able to cover all the content in depth. So, make sure to prioritise. What subjects do you struggle with most and which topic within those subjects cause that? Don't say all. I do it too but there's bound to be at least a couple that suck more than the rest.
Once you've identified those weak points, start summarising those notes to the very bare bones because you don't want books and books of info to learn. For example, in religion, I wrote out all the quotes for each of my weak topics and that helped so much because I didn't have to keep flipping through a massive textbook.
I'd also recommend teaching people. Even if they don't want to hear about it, talk about it. Even if you could just pretend to have a conversation with someone! Teaching is one of the best ways to get things into your brain long term.
Finally, do past papers. Don't even bother revising first. Just get straight into the past paper and complete it to the best of your ability. Make sure that the mark scheme is available because then you can go over it and highlight all the bits that you didn't understand. Open your notes and rewrite your answer how you would if you had those notes. Then read over those bits and redo the paper to see how much info you've absorbed.
Watching videos is also really helpful. I'd say just skim through them if you're really pressed for time but visuals can help you remember things so well!
Also, don't be afraid to ask teachers for revision material or help after-school! I'm sure they won't mind

Subject specific advice

sorry tho I don't do sociology!)
Biology- Biology is very practical heavy so I'd make a notebook or booklet or something with every practical in it because a lot of questions relate to that. I also think mindmaps are very easy to use for biology because everything relates to each other.
Chemistry- Okay, I'd find what definitions you need on the specification, and write them on flashcards. Seriously, chemistry is so definition heavy it's not even funny. Quantitative chemistry also comes up literally every time so make sure you understand how that works! In my opinion, it's genuinely the most important part of the exam because there's like six questions attached to it. That's so many marks! There's not really a way to revise this though unless you just do the questions.
Physics- make flashcards of the equations and the units. Basically if you know your equations, I guarantee you'll score even higher than a 7.
Maths- I think the Corbett maths booklets are very handy to print and complete in your own time. There's lots of past papers available for maths. You should do as many as you can because it's the most effective revision technique for maths. You can also create a hearty maths or Sparx account. I'm personally not very fond of them but lots of people learn well with the online questions and video explanations.
English lit- make a table of the characters you think will come up and have around 5 to 7 quotes for each character. Be aware of the themes of the novel(la) too. Remember, no matter how far-fetched something may seem- write it down. Just analyse it whatever way you can. Additionally, make sure to structure your analysis well- I use PETER paragraphs but there are many variations so use whatever you like most.
English lang- you can't really revise for this, just be aware of language devices and cram as many into your essay as possible. Write some essays as practice, oh! Time yourself too! That's a huge problem I find with writing essays.
Religion- I'm doing ethics and I don't really know what your focus is on but remember life arguments! Always include Christian teaching of some kind and agree and disagree in ten markers because it's extremely difficult to achieve full marks otherwise. Also, don't be afraid to ask the invigilators for extra paper. The lines available are really small and if you know more information- you might as well write it down (even if it seems like a stretch)
Geography- Case studies yield the most marks and there aren't even that many so make sure you know them inside out. I would create a poster for each one and hang them up on my walls. Procedures are also important but there's lots of them so I wouldn't worry as much about them. Just remember to always mention that they take a long time because you get a mark deducted without that.
Sorry that this was so long-winded! I gotta get back to my own revision now but I'm sure you'll do amazing in your GCSEs! It's not too late for us ❤️ good luck