I think it is never too early to start revising. You could start now by doing as little as 20 minutes a day.
One suggestion I have is to make sure you are not just recapping the content without actively engaging with the content. For example, just reading and making notes from your textbooks is not usually enough. Instead, try actively recalling everything you know first, essentially retrieving the information you know from your brain, this helps you find the gaps in your knowledge. And then you do it all over again, recapping everything you know (this time with, hopefully, your new knowledge) and finding the gaps.If you are curious about this method I would encourage you to do some research on it. There are loads of videos on YouTube