I am actually much more anxious with more long time and closer friends, than with new friends or people I just met. Mostly due to running out of things to talk about. Every thing new about me, they already know so I would just end up repeating myself in conversations. And it doesn't help that I don't really have much interesting and new goings with my life. This is probably a major and obvious reason why I have trouble keeping friends around for too long. My boredom and lackluster life just drive others away.
Enjoy any good things, even the little and menial ones, as you will never know what impending distresses could descend upon you in a moment.