I totally understand; I mess up with my time management all the time and I always end up staying till 3am to finish my a level history essay. I would advise making your revision sources way early and condensed so it’s out of the way. Yes repetition is key and if this is effective for you (the spec thing) then you’re doing great. However, don’t forget to practice from time to time - maybe after each topic you could do questions based on that? Id advise you to have a big emphasis on practice papers closer to the exams - I did this 3 months before my exams but you can do whatever you feel is right.
For history, hopefully you got the same question as when I did my history gcse: you get a source question, an essay question and an evaluate question.
For the source question, Use AEO (Argument, Evidence, Own knowledge): write out the argument; then evidence in the source that supports it; then I would write something you know that’s not mentioned in the source that is relevant to it to support the argument. Then I would use NOP (Nature, Origin, Purpose) to evaluate its reliability: Nature, what type of source is it like if it’s a diary, it could be personal and biased whereas an academic journal would provide facts on both sides and will be accurate; Origin, if it’s a primary or secondary source (look at the dates to see if it’s near the time of the event); Purpose, what does it intend to do like if it’s a propaganda poster, it’s not reliable since it’s biased to one side.
For the essay question, it would be something like why was ... significant / important to the.... This is simple because you can use what you know in English to history. Basically you need an introduction, 3 (or more) main paragraphs and a conclusion. For the introduction, write out a direct answer to the question, explaining how it is important or whatever it asks you to do. For Main paragraphs, you explain why you think this in more detail with PEEL (Point, Evidence, Link to the question). An conclusion is evaluating what you said and maybe having your own opinion.
For evaluating, normally you get a statement where you need to agree/disagree. Firstly, you need to make a plan of things you know that agree/ disagree but remember it’s a quick sketch of notes. Then you make an introduction, two agree (or disagree - whatever you think is more important), two disagree (or agree) then an conclusion saying which side you’re on with evidence to support it.
Don’t worry about remembering too much as long as you can still make an answer with it - it doesn’t need to be perfect. Good luck btw