I was getting the headaches even with relatively moderate consumption (a single-shot mocha or 8oz coffee in the morning, black tea in the afternoon, maybe a soda here or there), so I quit recently. For a few days I was quite miserable to be around but now I feel a lot better. I still have hot chocolate and the occasional candy bar so I get some caffeine, but no more coffee, mochas, caffeinated soda, or black or green tea.
For me it just sucked if I didn't get my morning drink, I had a headache by afternoon.
I still see people at the deli counter at my office who order 24oz lattes with 4 shots of espresso, and just shake my head. That dose would probably cause my heart to explode. Let alone the cost (I figured at one point if I bought one mocha per workday until retirement, I'd give my office's coffee cart $10,000).