Hi! Not doing the topics that you are so I can’t offer anything too specific, but I’d recommend reverse-engineering essay questions to see how much you know. Start by picking an essay q and attempt a plan. If it goes well, move onto another theme/period. If it doesn’t, look at the indicative content and focus your revision around learning that. I make knowledge organisers to condense all of a topic’s info onto 1-2 sides of A3. It helps me if I can see all of the info in front of me. You can then take revising it in little chunks at a time, working around it until you’ve got all the info down.
Doing it this way also gets your fear of confronting an essay (and an official paper) out of the way with. Taking it in small, manageable chunks is the best approach. Condense down any notes you currently have and condense again if possible!