Hey, I've always been a crammer and it's always worked for me so I've never really stopped doing it.
What I do is read through the entire course first, I don't know what subjects you do but I do three essay-based subjects so I guess my advice is limited if you don't do essay subjects.
I read through the entire course briefly, not memorising or testing yet, just reading to make sure I understand the material. If there's anything I see and I have no recognition of learning it, or understand it, I'll make a note of it, and then it will be the first topic I look at in depth. After I read through the course, I start to look at any topics I know I'm particularly weaker in. I write essay plans, memorise them and the information, put my hand over the information and say it out loud to make sure It's going in. You unfortunately can't spend too long doing this as there is a lot to cover still. Do this for every topic, if you have time. Topics you are already confident in, just gloss over them and look at them if you have time at the end. Again, not ideal, but it's not like there's time.
Do past paper questions, try do them from your own memory, but don't be afraid to use your notes if you need to. Although you can try to do it by memory then use your notes after to add any information you missed. You'll actively learn by using the information in a question-setting. If I find myself not remembering something about a topic, I reread the entire topic, before trying to memorise the key facts.
You don't have time to learn every single fact in depth, so pick things. Pick a couple of statistics, or people, dates, events, etc and just learn them. Preferably information that you can reuse across the entire exam paper. Ultimately, you need to make it look like you know your stuff.
Make sure you have at least a BRIEF understanding of everything first. Then start to learn in depth, starting with things you're weaker in. It's possible, it will require a lot of work, a lot of hours a day, but it's a sacrifice you have to make if you still wanna do well.
Good luck though, try not to stress, exams aren't the end of the world ngl