Dissertation Proposal

My dissertation proposal defense is tomorrow at 1pm. I have to present my proposal and they decide to let me start the research or make changes to the proposal and try again. I'm not getting anxious. For some reason I'm getting depressed instead. I just have this feeling that I don't want to work on the presentation even though I know I need to. Basically, this sense of depression is keeping me from working. I just don't want to defend my proposal tomorrow... or ever. I don't know how grad students actually manage to finish...