I truly believe most of what people complain about, symptomaticlly, are D/R to porn. Being medically trained and heavily knowledgeable with the clinical/biological sciences I can solidly state that we know very little of pornographic related additions other than the relation is shows towards neurogenic (neuron/ chemical) models of addition. It's how we understand the role of dopamine etc.
As far as the headaches, I would have to say that it could be due to recovery etc. Like I said, if it keeps occurring you can always have it checked out.