I prefer being by myself, really always have. People make me irritated, tired, and anxious most of the time. This frequently causes static with my wife and two sons. They take my agitation as being angry or mean when really I'm just overwhelmed very easily.

I get sweaty/racing heartbeat/flight urge in nearly every conversation eventually (sometimes in anticipation of one). This is especially the case with impromptu convos, and even more especially at work and church. It is very difficult to stay engaged - I focus on how I must appear to the other person/people in the conversation. This leads to me fumbling over thoughts/words and becomes a cycle. Afterwards I ruminate/analyze/criticize myself.

Therefore I prefer to keep to myself as much as possible. I think that makes me introverted.

Oddly enough, back in my later teens I had a personality/career assessment done by a psychologist after I was kicked out of university. The assessment indicated a high level of extroversion and dominance in interactions. In retrospect, I perceive that period of time as my first hypomanic episode. I therefore attribute the deemed extroversion as further confirmation of such. Even then, I preferred myself as my own best company.

'Never lonely when alone' - I read that in a birthday horoscope years ago and it has always struck me as so accurate about myself.