New Friend

What is a friend? I tend to think of a friend as someone who I can relax with, have fun with. Simply, someone who brings me happiness. If so, then I have friends in almost everyone I know. What troubles me is, if I have plenty of friends, why do I feel alone? Why is it that when I am upset, I can't find myself comfortable enough to confide in any of these friends? Shouldn't a friend be someone who can comfort me? Or at least someone I can find comfort in? I can't help but feel alone often; even frequently. So I wonder, is this what growing up is? With age, is loneliness a new but permanent friend? I suppose everyone eventually reaches this point of maturity where a truth is uncovered; that everyone has troubles. This point is where the previous selfishness of our youth is exposed. Our once constant need to share our problems and pain with our friends is gone. I am not speaking rhetorically. I really do wonder if this is part of becoming an adult. I want to understand my loneliness. I want to know if I should learn to love this friend. But most of all, I need to understand how I, someone with many kind people to help share my life with, can cry many loud tears that no one will ever hear.