Kari,
I spend 98% of the time on my own. I don't like being around people, I prefer quiet. I maintain my equanimity through insularity. I have no need to apply a DSM label to my life style preference or pay some quack to tell me I have a disorder.
I am just a person that likes being on my own.
Be very careful if you decide to go down the path of consulting a shrink to get a label. Do a lot of research before hand and think of the consequences of entering the world of becoming a "mental patient". Make sure you fully understand all the legal implications associated with a "diagnosis" both now and in the future.
Not liking people is not an illness! Psychiatrists will gladly tell that it is but their agenda is profit and power.
If you're cool about not liking people, leave it at that. There's nothing wrong. It really sounds like you had an awful job with awful workers and that you didn't like. I mean, when it comes to people, what's to like???
Have you thought about changing you're lifestyle? I'd do that (even though it is difficult) first but only if you're under distress. You don't sound like your distressed at all; just curious on why your preferences are different.
Have you heard of Jungian typology? It is the most used psychological tool in organisations for identifying personal preferences. Organisations use it for team building, reducing conflict and increasing productivity et cetera.
Here's a link to a test that may shed some light on your curiosity.
http://similarminds.com/jung.html
When you get your 4-letter result (it will look something like this "INTJ") type those 4 letters into google and have a search. You'll probably find you're one of the rarer 1% types and that why socialising isn't a strength of yours. Then hopefully you can learn to focus on your strengths.
PS: When you are doing the test there are no right or wrong answers, the test is about establishing preferences.
Good luck.