Ok, I admit that the overly-positive attitude of our mc sooommmetimesss rubs me the wrong way, but this chapter...was an actual valid way to deal with negative thoughts.
In a few words: ok, you can't help fearing that what you worry about may come true (independently of how probable it is), but that also applies to the positive things it may happen. May being the key word for both sides.
For every negative think also a positive, yeah~