Well written post.

Hui Peng was still young, so her insecurity and reliance on others to fulfill her life is acceptable at that age.

Fear of being alone is similar to many phobias, we all have our phobias and some are more severe than others. I am no psychiatrist or physiologist. But one way of conquering your fear is to change the definition of being alone.
Firstly, you can be in a train station surrounded by five thousand strangers and still feel alone. Or you could be in a house party with your closest friends and still feel lonely.
Secondly, in this day and age of digital world, we connect with others in many different ways, be it social media, instant messaging or phone call, we can easily connect with others and be with others from the comfort of our smartphone.
However, if you have the fear of being alone because of a traumatic experience (such as kidnapped), then it may be a better idea to seek professional help.