It is an entirely unforgiving and often heartbreaking trait . So now I cherish the past and struggle with the prospect of the future . There is not a fucking doubt in my mind that this will be worth it . He is my world , and my deepest , my only love .

Options: A. she is worried about studies; B. she like breaking hearts; C. she is worried about his friends; D. she 's worried she wo n't find another like him;
Answer the following question: why does she struggle about the prospects of the future ?
D.