I think i figured out my problem:

And it's a catch-22. Not simply that my problem happens to be a catch-22, but that my problem IS catch-22 (not the band... they're still my favorite). And by nature, a catch-22 is always a catch-22. Isn't that just the best kind of problem to have?
I concur.
Anyways, let me lay it out for you like this:
I am a pessimist. I do not think happy thoughts. I don't have hopes or dreams, or aspirations. And if I do, they're for bad things, or things that I convince myself aren't worth pursuing. If in the rare event that I ignore my initial warnings and pursue something worthwhile, there always, ALWAYS, without fail comes a point at which I convince myself that I cannot succeed, and often that I have already failed. In essence, what makes me unhappy is overthinking. I overthink everything; I evaluate, estimate, and predict situations precisely and constantly. And due to my nature, the end result is never good.
Example: Everytime I am in the car and another car gets too close, or a car swerves quickly, or someone slams on the brakes, or even if I just get distracted by thoughts of the speedometer, my thoughts always flash to the end result of an accident. If I was in an accident just then, what would my mangled corpse look like? I always like putting my right arm behind my head, so it is generally dislocated and frequently detached as it is crushed against the headrest by the side panel of the door. Of course, the airbag's on, so my glasses are shattered. Bits of the frames and possibly the lenses are buried in my swollen bloody face. My nose is pulverized, an indistinguishable fleshy lump on my mess of a gap-toothed face. Odds are, I bit my tongue off, or bit through a cheek. My knees probably slammed into the dash board; the patellas fibias, and tibias are crushed. My femurs are slammed backwards into my pelvis, crushing into the sockets. In short, I am dead. Blunt force trauma, implation, exsanguination. All that good stuff. It happens.
Now, correct me if I'm wrong, but I don't think it's considered "normal" (read: "healthy," "sane," whatever) for this to be a common or frequent occurance.
So the simple solution: Just stop thinking about it.
There's really nothing simple about it. The only simple truth as far as I'm concerned is that thought is the only undeniable truth. Life and death are often heralded as the only truths, but without thought, neither holds any weight. What is a life without consciousness? It's being an inanimate object, which are hardly alive at all. What is death without awareness? A long sleep. That's all. If we didn't think about and seek out to give everything meaning, they wouldn't have it. And that's where the catch-22 REALLY kicks in.
The way I see it, it's pretty obvious that my problem is that I think too much. So the alternative is to think less or even to stop thinking at all. But then existence is fleeting. Without utmost awareness and maximum analysis, there is NOTHING.
But of course I have to choose one over the other. There is no compromise. And I choose thought. I suffer every day. It's like living in a nightmare every moment, awake or asleep. There's nowhere to hide. No safe memories, no hopes for the future, no light at the end of the tunnel. Being an antitheist, there is nothing after this life, and as a nihilist, nothing worth living for in this life. As an absurdist, of course, I am almost obligated to choose thought. But without the prospect of fleeting feelings of happiness, I have less to look forward to than any Meursault. When I really think about it, there's not even a cause for morality. But in this society, to avoid confrontation and interaction the best way to go is unnoticed.
I guess what I'm trying to say is LEAVE ME ALONE.
I only make people miserable. Even if I seek out to create connections with people, there is a constant threat of betrayal lurking around the corner. I believe in the inherent bad nature of humans, and as a result, I always manage to sabotage any meaningful relationships.
What this means, in essence is that I will be a hermit.
It's really that simple.
I'll get a degree (or not), get a job (or not), telecommute, and live alone off of my salary (or welfare), ordering everything I need - including but not limited to groceries - off of the internet to be delivered to my house. If I'm lucky (which I rarely am), I can file for permanent disability and get a trained service animal.
I'll have cats, and the only people that I will ever see will be Daniel, Michael, and my nieces because they are the only creatures on this earth that I have the capacity to love. I will be scarred, bruised, and broken, just because it's second-nature to self-inflict pain.

And then I will die. Since I honestly just can't picture myself dying by anyone's hand but my own - nature included - it will probably happen on a slow winter day, probably about 30 years into the future. I'll go outside for the first and last time, and lay in the snow (of course there's snow where I live) and kill myself. I'm thinking a bullet to the temple. Worst case scenario, I'll die in my sleep, in which case I will rest in peace knowing that I murdered myself with by long-term alcohol- and drug-enduced poisoning. Noone will miss me, with the exception of my now-starving cats. In any event, I hope there are tears on my leather-hard face. It will have been years since I had cried, but they will be tears of joy. What could be sweeter than release after a life of inner-turmoil?
And that's my problem. If you have a solution, shove it. Seriously, I don't want to hear it. Just let me be, and noone will be hurt. If you reach out and I deny you, I take no responsibility for the hurt you suffer. It's what you get for making yourself vulnerable to another human. Maybe you'll learn from your mistakes, and everyone will come away from the situation better. Except me, I'll still be the same. Except maybe just a little bit more frustrated.

UPDATE:
This was just a one-night episode I had. I kinda freaked, for whatever reason. I still think a lot of this is true, but I just hope my predictions for the future are slightly off. Only time will tell.