What Causes Headaches?

I've recently started having really heavy feeling headches in the centre of my head and behind my eyes. It would be described as a dull ache. I've also started having hot and cold sweats which, when they start, make me feel really faint and worried that I'll pass out. I've also had really intense university exams lately so I think it's psychosomatic but it's really debilitating and comes on in social situations