strong coffee and sweet chocolate

Sometime last September, I was in Manila for a certain appointment. On my way back to my home, I dropped by to this coffee shop for a sip of coffee while waiting for my plane. I ordered just a cup of coffee and two different slices of chocolate cakes: Double Chocolate Walnut brownie and Chocolate Peanut Butter Bar.

Double Chocolate Wlanut brownie.........Chocolate Peanut Butter bar

While having coffee and some cakes

Hmm, the coffee is great! and the chocolates taste delicious!... Minutes passed, as I was about to finish taking my coffee and mucnhing the cakes, I feel something bad.. Gosh, I got an awful headache.. I wonder what causes the terrible ache, does it because of the caffeine, which both chocolate and coffee have it, or maybe I was just anxious of my whole day activities....