And I'm quickly finding out about the limitations of caffeine. I'll try to get more sleep, though.

Thank you again!
Just to friendly hammer in the importance of breaking caffeine addictions: it's story time!
Back in Fall 07 / Spring 08 semester, I worked as the editor of my school paper, a bi-weekly with 3000 circulation. We had a core staff of 3 people including me, and about 10 writers that worked for free due to budget issues. Needless to say, I pretty much slept there during the weekdays, and would go in on weekends since I had 4 classes each semester, in addition to doing some janitorial work (for my grandpa's company, I was spoiled in that regard). To deal with this, I would chug a pot of coffee a day, and combine that with 5 cigarettes! A few months after I quit this cycle, my body went through complete atrophy!
What made that situation perfect, was it coincided with another wonderful event, which ended up giving me
ptsd! A couple years later, and I'm finally fit to work well 18 hours per week, while taking 3 classes per semester. Thankfully, I'm down to a cup of coffee a day, along with 2 cigarettes.
Right now, the longest day for me is Wednesdays, as I work as a stock guy for a hardware store and open at 7 a.m. and get off at 12 p.m., from which I rush to my 1 p.m. class. Then, I have a break, and to mellow out I go and pick up comic books (they are always released on Wednesdays, thankfully), and that gears me up for my 7 p.m. to 9:45 p.m. class, and then the drive home!
If you find something to help you regain your personal focus, and bring about a sense of enjoyment, in between your drive from work to school or whatever, it will help. Granted, the side effects of caffeine withdrawal will come upon you either way, but over time things will get better!