You shudder to think of what may go wrong, but that is because you are thinking of what may go wrong!  That is where your focus lies, and your body does react in kind by shaking.  Do you see how body-matter follows thought?  You would not shudder at all if you did not consider awful things as possibilities or consider possibilities as awful things. 
Take all possibilities back to neutral, and decide how you will interpret them.  If you wish to shudder and be frightened, then go ahead and place your focus on fear.  Interpret situations real or imagined as frightful, but understand that all is perception.  You can take the most frightful or awful event you can imagine (and my, can you not do a wonderful job at this?), and imagine it now from the perspective of higher consciousness, where you can see all as a great drama playing out.  Sit back and watch, and when things get too frightful, shudder not, but change the scene.  You do this in your mind with your interpretations.  Shudder to think what might happen if all human beings took control of their thoughts … then there would be no need to shudder at all.