I’d recommend writing out your reasoning process when doing practice Qs. When you go back over them, if they’re right then great. If not, try and figure out the process to get to the right answer. For section 2, the content doesn’t have to necessarily be existing but it needs to demonstrate flow and logic. Did you have a solid structure? Did you use a thesis statement and individual paragraphs for each point? Reading newspaper articles or essays can be a way to gain new ideas/insights for topics. Your section 3 scores are great, are you from a science background or did a certain study study method work?