Oh, I think I somewhat understand what you're going through. There are a few differences. I was addicted to caffeine also, except I don't like coffee- so I turned to Coca Cola (I know, tons of sugar too- really bad) for my energy. For a while, it was Jolt soda and the caffeinated Vitamin Water brand soda, which I don't think they make anymore. I knew it was really unhealthy, but I didn't think I could make it without the caffeine- I was so tired ( 4 children under 12, and the last three each had reflux).
As you can imagine, I started having health problems- my stomach lining was totally messed up. (Not just from the soda, but took a lot of pain killers like high doses of ibuprofin over the years because of 3 c-sections and some other surgeries.) A burning stomach is a pretty good motivator to stop the soda :) In addition to that I had palpitations (which really scared me- thought something was wrong with my heart) , dizziness, anemia, severely low Vitamin D levels, and was suffering from depression.
I pretty much had to quit cold turkey (which I don't recommend unless you have no choice). I felt horrible- debilitating headaches (couldn't even take ibuprofin because of my stomach lining). My mother actually took my kids to her house for a few days. I started drinking a lot of water, which did help some. I think the more water I drank, the better I started to feel. I started taking iron (which I think helped the palpitations), a prescription for high dose Vitamin D, and an anti-depressant.
Anyway, now I'm much better- no more coke, and actually don't even miss it. I still try to drink as much water as I can, and oddly enough, I have more energy than I used to. Go figure ;)
I think if you can taper off, you won't have it as bad as I did (although you still might feel crummy for a while). Just make sure to drink a lot of water. I'm not sure what your situation is, but can you take some time each day to relax? Or, at the very least, find a way to get more sleep? You may have to let something else go (I had to stop being so picky about how clean my house was). Do you like De-caf? I was surprised that despite the name, it still has caffeine, just not as much (my Dad had to give it up because of high blood pressure) Anyway, that might be a stepping stone for you. My Dad's doctor recommended he drink green tea, so that might be a good alternative drink for you.
Here is some information about caffeine that you might find helpful:
http://pol.spurious.biz/dev_zero/caffeine.html
Anyway, I wish you luck- sorry for being so wordy, but I hope it was helpful :)