Remember, I didn't just mean psychologists. If you have options to see a medical doctor, check with one as well. Just because you've had traumatic events doesn't mean you should rule out a condition that it's bringing out.
> I know this is just the stupid angst of an angry 18 year old who's problems are probably less severe than what you are facing, but it's all I know. Please understand that.
I hope it's just that. In any case like this we can all hope it's just that, because that one can be healed by time. I'm not the judging type, especially for depression. But please, make sure it's "just" that.
You're young. And I don't mean, "you're young, so what you're going through isn't important", or even "you're young, you'll think this is silly in a few years". You're young, and a lot of the things that can significant effect on your state of mind, even at 18, are still in development. You're at one of the most dangerous periods of life for anyone, statistically speaking. Talk to people, take care of yourself, do something. Don't ever let yourself fall into a lonely cycle of self-discussion. I'm sure there's plenty of people here who can speak from experience that this will not help your mental health.
Also, if it helps, so far as I've ascertained, psychologists don't psychoanalyze you unless they're dipshits still in college for psychology. If they're being paid by the hour, chances are they're looking for a cause. But again, I'm definitely in the "medical experience > psychological experience" by an order of magnitude, so please check with a medical doctor, first.