Hey!
Firstly, well done on gaining such good predicted grades! A great way to start the year.
Now, I would suggest as it's only November now you have time to create your own decks for every single aspect to force you into revision. I used to go and use others and often felt it missed information or focused on cards which for me were "too easy" and I was already familiarised with. Secondly, in my opinion and this can be different for other people's study methods however, I found through the process of actually creating the cards and then reversing the information into questions for anki cards would assist me in just gaining/reinforcing my basic understanding. Statistically, this isn't the most effective way of revision by just making notes but it's the actual as you mentioned the spaced recall and repetition which will assist you in ensuring you can learn everything in the long term!
What I used to make them, I did only sciences and maths so I used:
Spec - which is your best friend
Mark schemes - every bester best friend
and any textbooks etc.
Mainly a mixture of those to create my own answers which I know hit those buzz words the exam board want and will gain me marks.
That's my personal experience, naturally everyone's different. I'd say overall, give it a shot for a week see how you go! Worse can you can go back to using other peoples which isn't a huge deal tbh.
I'm studying medicine right now and I make ankis through my lecture so on average I make around 3 - 4 decks a day. But, that suits my current revision plan and day to day schedule
Any further questions about anki feel free to ask!