How to make a one-year study plan for a difficult exam and remain motivated throughout?
I would recommend you not to rely upon external entities for motivation. Rather then relying upon just some books and software, practice "Self Motivation".

Each day think about the happiness and satisfaction that you will achieve once you got an admission in the targeted postgraduate school.

Furthermore, browse through the list of notable alumni from the same school and make a target that you will also feature in the same list some day. 

It will encourage you to put 100% effort each day without losing excitement.