It is common for the student to be given some time for self-study, before the instructor works with the student to reinforce that study and eliminate any weak areas. Confirm with your instructor that he
will be working with you on this before your exams.
The DM academics can be a shock to students, especially if they have been outside of a formal learning environment for many years. However, there will come a point where it all starts to make sense.
You
should have a copy of the Encylopedia of Recreational diving to assist your studies. YOu might want to investigate the electronic copy of that also... it is interactive and has lots of good video clips and supplementary info to make things interesting. This, along with many other learning materials, may be available for torrent download, if you searched
Of course, being a valued member of Scubaboard.... you also have an amazing resource at your fingertips. There is a huge wealth of well-explained information here on the forum, which can be searched for. In addition, I am sure that many of the instructors, DMs and other experienced divers here would be happy to assist you
Good luck with the study. It'll all become clear in due course!