I was thinking about test, how I should be calm about it. Then I feel my body to check its condition. Then I went back to thinking as I feel that something is amiss yet. So I think about the holiday. What I did wrong was to not know more about my physical state.

The physical state is not enough to know that it is tired, hungry or know your surrounding. You must also know what usually happens in this situation, like when tired you will closed your eyes frequently and tend to go to the bed to rest frequently. Because this reactions are happening now and later so they are current affairs. Knowing them will enable you to adjust your expectations, and decide what to do correctly.

Your body will always be stuck in the present and soon moment first. The problem that I face just now that I was not aware the characteristics and reactions of my tiredness and instead allow the tiredness to be put into my thinking of the test.

You do not understand well the present moment and its feeling and effects, and separate them from your thoughts.