I am a retired university professor who had the pleasure of reading many of these types of assignments. Early on in my classroom instruction I tried to laid out the process of authoring a thesis on the front end. Yes, I said author! Because, after all, it is supposed to be an original piece of work which contributes to the field of study or discipline. I think you are suffering from what I call "scatter-brainitis." That is, without your professor's laying out just how a thesis is put together. You simply can't connect the dots. Then, when you realize the importance and magnitude of the project you freeze up, tune-out and find distractions (T.V. etc...). The best way to put a thesis together is to write papers for each of your core classes which will in the end contribute to authoring your final task. By coalescing the essence of you're papers you avoid the risk of plagiarism and have essentially already written your thesis. You just need to organize it, cite your sources and above all, enjoy it! It's like a shot - The anticipation is much worse than the actual event. Hope this helps!