I was in hospital and off work with severe head pains back end of last year and cluster head aches was mentioned to me by my doc as a possible cause, she gave me info on these but its in the bed room with my lass and the bairn asleep upstairs or I would have got it. I might be wrong but I think I remember stress/anxity being a cause of them. I would go to your docs and let her know straight away and get it checked out nowt worse than a banging heed mate.