I did look at your about me and any or all of your personal issues can lend to needing space. But everyone has their own need for personal space, it is just human nature.
And even animals need that and I think it is a part of our sense of needing space at all times so we can escape from any harm. I really think it is a built in defense mechanism that everyone has. There is a term called "PERSONAL SPACE" and a lot of books and advice about defining your own personal space and how to respect the personal space of others.

Open Eyes