My head hurts. I think I'm having caffeine withdrawal headaches. How long does it take to adjust to less caffeine. I'm going from a morning cup of coffee to a morning cup of green tea and sometimes black tea. Occasionally an additional cup of tea in the afternoon. On the weekend, a cup of tea and/or a small cup of coffee. Not no caffeine, just less caffeine. And I've been headache-y. I do not like it. Stupid head. Stupid caffeine.