I need some kind of motivation

You still have around 2 months around the main exams. I suggest you start off just reviewing a bit to get familar with the materials. Then you start doing practicing exercising or whatever you do. Then you do a 3rd time and pay attention to stuff you have more difficulties with. But start off lightly. The motivation will come gradually. Good luck!

Honestly, I wouldn't study this early either. It isn't even April 23rd yet! I would wait another month or so before even starting. Then I would sit down a make an organized list of what I need to accomplish and how I was going to do that. Then take action.

self-hypnosis before you sleep,relaxes and tell yourself:"I will do it well!" the same like those words,gradually,you could find you have been do that well.I did it for a long time,it's very useful.

What I usually do is Think of all the things I can and will do after the exams get over. Then I decide upon a suitable reward for starting the learning session earlier. So I finish off my studying beforehand and also have time for revision and giving a small reward party for myself. Or if you are comfortable with smaller periods of studying, you can study a small portion and take a break for some time and relax listening to music or do whatever you want to do. This usually works for me.