I clearly have some kind of vice related to caffeine...
In the hardest periods of my life I managed to guzzle 6 liters of coca-cola every day, plus eating lots of chocolate, and drinking lots of coffee and tea, of course this also ruined my overall health.
I recently managed to "get clean", but I also stopped working, then I gave up, decided to buy 1 liter of red-bull style energy drink (not redbull itself because I can't afford it), drink it all in one go...
then I could work, and I felt MUCH better... but I am also drinking lots of coca-cola and eating lots of chocolate again.
I am seeing a psychiatrist, and seemly I have ADHD, and caffeine (and other stimulants) are a common way to self-medicate, and many ADHD sufferers, specially those not on legal meds, end having some strong vices (not only stopping at caffeine... cocaine, meth, and other strongly stimulant drugs abuse is also common).
I started taking Ritalin (Adderall is illegal here) this week, for now only half a pill per day, because my psychiatrist is inexperienced and probably wants to be safe, let's see if with it (and an increased dosage later) I will be able to stop abusing caffeine, my kidneys (that had stones) and my liver (that is covered in fat to the point of failing to work properly) will thank me. (I am also going to a psychologist...)