Any chance you're in the UK? I took my degree there/here and Mother of God, do those people love exams!! A whole year of classes, lectures, etc. determined/evaluated in one three-hour chunk -- and sucks to you if you are ill on the day or whatever!

I don't know if hypnosis will work because I'm not you. Those things are highly personal, you'd have to try it and see. I'm the Queen of cramming, but I don't recommend it. If lack of preparation is your problem, then obviously preparing is your solution though. I don't think hypnosis helps with that. You just have to find a way to make yourself revise. (And when you find out, let me know!)

I read a book once, 'The Procrastination Equation', can't remember the author but I think his forename was Piers. Lots of good tips in there.