There is this part in the book where it wrote about the difficulties and challenges Nabi Muhammad SAW had to face, hence, he asked Allah SWT :- "Can he handle the tests he was given, can he survive it, would he be given a direction where to lead?" Allah SWT turunkan satu ayat which was translated in the book which says "Hope for the best, don't ask too many questions, as I know more than you do and i will lead you".
After reading that, only then I understand. HE knows where it will lead me. All I can do is just pray and ask for the best and leave it all to HIM. Thus, everytime I feel sad, lost, unsure of what is there instore for me in the future, I would remember what Allah SWT told Nabi Muhammad SAW, and I felt relieved.