I ended up wondering if my tendency toward anxiety stems from living alone. When my girlfriend was less broken and able to spend the night I think that I was happier and better adjusted, after her back got messed up and she hasn't been able to come over I think I've been sliding back toward random bouts of paranoia.
I've certainly observed that I feel closer and more bonded to her when I can touch her.
On the other hand there was an essay arguing that people do no better at predicting the causes for their actions than strangers. I need better logging of the events in my life so I can perform statistical analysis on what actually makes me happy.
Also while looking for the essay that lead me down that path I found other interesting ones about how there are circuits in our brains that use direct feedback from the person we're interacting with that tune how we communicate. In pure textual media can more easily lash out and flame because those circuits aren't engaged. I've noticed that I feel less alone when playing an MMO than when sitting in my apartment reading, or even doing IM, and I think that's due to those circuits being given at least something vaguely human shaped to operate on.
I've wondered why I seem to be so unhappy with being alone, and my best guess is that humans evolved has a herd prey species and that being away from your tribe meant your were at increased risk of being attacked. Under that situation it would be a survival trait to be obsessed with identifying various predatory risks.
Because I've been alone, and haven't been able to trust my family for a long time, nor have I been able to maintain long term close relationships, I suspect this has left me more likely than most to obsess about the "predators" that I'm most likely to encounter--economic or environmental instability.
The key thing about this innate fear of being alone, is that its not quite being alone that's the problem its being away from people you trust. So just getting a random roommate, or hanging out in a coffee shop isn't enough.