Writers Block

Why is it when you have an important paper to write or have to say something your mind goes into shutdown, sleep mode. I have a 6 page paper to write for one of my classes that is due tomorrow. We have had the assignment for two weeks now and I'll just tell you I don't have much done on it. I am a big time procrastinator when it comes to papers. I just can't do it until I HAVE to. I work better under pressure I guess. I think the added difficulty to this paper has been that there is not an assigned topic. You would think that would be easier but for me it isn't. I do much better if someone just tells me what to write about. It's so hard to pick something from such a broad range of anything. Am I the only person that feels this way. Give me a blog and I can type your ear off. Tell me to write a paper and all of a sudden one sentence takes me 4 days. Well I better get back to pretending to write my paper. I'll let you all know how it goes.