Not sleeping a whole lot

Well, I'm not sleeping a whole lot lately. The last few years I tend to sleep at my desk or at a table, sitting up, then, when I wake enough to realize I'm sleeping--or close to it--I head for the couch I sleep on. I can grab an hour there, then back to the desk, then back to the couch. In the end I get maybe 2-3 hours of sleeping horizontally and the rest sitting up. Not great for keeping my ankles looking like kankles!
   But the last week, well, I've been getting up at 3:30 or so--last night was 2:37--and cannot go back to sleep at all. I've been making coffee at 4 AM and sometimes that works to focus my mind so that I can grab an extra hour--if I only have half a cup (and I make it half-regular/half-decaf) probably akin to the way add drugs cause you to focus.
  Think is, I don't know why I'm not sleeping. Even if it's half sitting up, I can generally put my head on my arms and go out quickly and pretty much stay sleeping for a couple of hours at a clip.
  And a night like last night, a 2:37 wake up, well that makes for a very long night. Darn it. Once in a while I'll take a shot of cough syrup or the over the counter sleep-eze caps, but I don't like being dependent on those so I keep that to once in a while. Aaarrrrrgggghhhhh! This not sleeping makes for huge bags under my eyes and my brain is not as quick as it should be.
  C'est la vie, but I'm not digging it.