All in all, unexpected quizzes, homework assignments and exercise deficiency are the three main causes of stress in my life. But I could make these unpleasant events less stressful. As an example, instead of watching TV in the evening, I might go to the Recreation center and do some aerobic exercise. I could perceive an abundance of assignments as a challenge to learn more and be successful in the future, and, finally I could suggest to myself that knowledge checking might be every class and prepare for that. If I did all this, I think I could significantly reduce stress in my life.

In this sentence:
finally I could suggest to myself that knowledge checking might be every class and prepare for that

I wanna say that if I suggest to myself that quizzes will be evey time (every class) anf if I prepare for them in advance - this will be less stressful for me.