Regarding resources, I would recommend finding all the online websites you can to get notes that are different from what you already have. Here are some I know
Also (for students of science), if you have a friend who retained or just any junior from JC, get their I/C number and use their LMS account. LMS has videos for every topic in every subject with the most basic things explained. You can replay it a thousand times to understand everything, nobody will judge you.
Students also like to enquire about how I studied so the following part is going to explain that:
You need to stay constantly motivated and that can be a little tiring. When you plan all the way to November be prepared to lose some weeks to circumstance because shit happens. My grandfather died in September and my relatives from India came over to stay for 3 weeks. I lost precious study time during those weeks. Be prepared for the worst.