No sleep for the weary

I have recently become a world-class insomniac. I used to hear people say they had insomnia and think to myself, "HA! I can sleep through anything..suckers." Now, I think the fact that I had those thoughts is manifesting itself with some sort of karmic retribution, and it is not pleasant.
I am tired for most of the day, daydreaming about when I can come home and take a nap or imagining going to bed at a normal time and sleeping the sleep of the content. But that has only happened about 4 times in the last month, and it's starting to wear on me a bit.
I think of that line from "Fight Club," in the beginning, about how when you stop sleeping, you never really know what's real and what's not. I probably screwed that up, but you get the general idea.
Seriously, after the first couple of weeks, I would just sort of feel like I was underwater for a large part of the day, and then I would get a second wind, but still not feel quite normal. It was an odd euphoric feeling, that would still allow me to be able to sleep for at least the first part of the night, and then at 2 a.m. was when the fun would start.
Now, I don't know what to think. I'm pretty cranky all the time, which was hard to recognize as a symptom for a while, I have headaches, and when I do finally sleep, I wake up so many times that by the time my alarm goes off, I'm never really sure if I was asleep or not.
It's kind of a maddening way to live. I've tried to pinpoint what may've set this into motion, and I honestly don't know. Sleep and I have always had a very fond relationship.
Had a rough day? There's my old friend Sleep willing to step in and lend a 45-minute power nap-hand to help out.
Been burning the candle at both ends for a few days in a row? Sleep knows what to do. A nice 12-hour refueling, and everything is back to normal.
I'm trying to decide if my body has suddenly realized that it's 28 and no longer wants to accept caffeine after a certain hour, which is what my sister suggested, but I refuse to be one of those people who says that drinking a Coke after 1 p.m. will keep them awake for the rest of the day. I'm not THAT old, Jesus.
I will never forget one of the funniest memories I have of my friend, Brian. We had been dating about 3 months and had taken our first overnight road trip to Huntsville, Ala., to see my friend Layla.
We had been out having a few beers and had headed back to our hotel for the night. As we're going in, I stop by the vending machine, as this was during the "Mountain Dew..to hell with my kidneys" phase, so that I could dose up on its sugary goodness.
Brian says to me, without a hint of irony, "You're getting a Mountain Dew. Well (insert old man voice here), don't keep me awake all night after you drink it," as though I'm going to finish drinking it and immediately start pole vaulting around the room.
I found it so funny, in fact, that I laughed, rather loudly, for about 5 minutes, the entire way it took us to get to our room, and I'm fairly sure that I kept laughing well after we got into it.
Now, who's laughing? Now that I dread actually putting head to pillow at night, because I lie there (blink, blink), tossing and turning for 2 hours, I may actually have to conduct a series of experiments that may involve cutting off caffeine in the afternoon to see if that's what the problem is.
I'm off to bed (again). Wish me luck.