it sounds like you have a sensitivity to caffeine.
Did you cut out all caffeine? or just the obvious ones (coffee, tea, pop)?
Caffeine can definitely increase your anxiety and cause palpatations. Many doctors will advise people with anxiety and panic to decrease or cease caffeine consumption to help. Caffeine is a drug and you can build up a tolerance to it fairly quickly. It is a stimulant and you can have stomach cramps, inability to concentrate, headaches, etc while you quit, but I agree once you are off of it, it really does help with anxiety although I need it to get up in the morning :).
thats what i need to do, i have been addicted to mellow yellow since i was 17, i can't imagine what i would feel like if i tryed to quit. what are the w/ds of quiting caffine?