I am a procrastinator. I've always been a procrastinator. Whenever I'm faced with a non-optional task of some complexity, typically writing, I become a nervous wreck who logs into Facebook, refreshes his brokerage account, plays Minesweeper, and straightens up the house, constantly and compulsively. I took at least three incompletes in undergrad and when I earned my teaching license. All of them were for term papers. All told I have been pretty successful in school and work, which surprises me sometimes. I suppose I must be pretty talented otherwise; my ability to manage myself and my time is so heinously bad that it is hard to understand how I've ever managed to compete with well-adjusted, steady workers.
I have learned that people who don't procrastinate don't understand. Words and rational thought don't help. Incentives don't help. Taking care of yourself - diet, exercise, sleep - doesn't help either. Self-discipline is a foreign concept. My willpower is too weak to break procrastination head-on. Procrastination is utterly, terrifyingly, paralyzing.
It finally took confronting the mother of all procrastination triggers - Ph.D. research, mine in physical science - to find a way to cope other than pulling an all-nighter the day before something is due, using extreme deadline pressure to push me over the horrendous activation barrier separating me from productivity. Running on deadline pressure simply became impossible when the work products that matter are completed in hundreds or thousands, not tens, of hours, and deadlines became virtually nonexistent. When I finally had to quit a research group under pressure because I'd had a manuscript "in preparation" for too long, I realized I could not succeed anymore without doing better.
Ultimately what resonated with me was an emailed invitation to a seminar on procrastination at my university. I did not attend the seminar, but its invitation mentioned procrastination as rooted in anxiety. You mentioned stress in your post. I do believe that, while other aspects may vary, the positive feedback loop between delay and anxiety is very common if not universal. For me, the anxiety is rooted in perfectionism for the appearance, function, or logical structure of a product. So it is not hard to imagine how a 2,000-word - or 10,000-word - document trips me up. For me, the resolution of this anxiety is to be immersed in process, having an intuition for where I am in a task as it is linearly, effortlessly completed. For others, the source of anxiety and its release may be different. But for every procrastinator I've gotten to know well, I've seen that their syndrome is, deep down, all about anxiety.
For me, to reconcile these two required a way to get into the process using willpower. And to give one's will a chance against a wall of anxiety, the process had better be easy. The trick I use is to break a job not into small pieces but TINY pieces. And I put a definite time limit on completing that tiny piece.
So I find myself saying things like, "I'm going to go to the office, and within five minutes of turning on my computer, I'm going to write one sentence." On its face, this is ridiculous - the task is to send a manuscript to Physical Review Letters by the end of the month, not write a sentence. But that trick of coming up with a job so small and definite that willpower can break the logjam is, to me, crucial.
Sometimes I fail to complete even the tiny piece. Sometimes I complete it and immediately slip back into unproductivity. But other times, certainly often enough that it matters, my brain starts working, I fall into a groove, and a lot of work gets done.
I'm still a procrastinator. I probably always will be one. Tomorrow I have group meeting and there's one last figure to finish for the paper I'm working on (let's not talk about the text!), and look what I did with my evening instead. But using the technique of doing tiny tasks with a time limit has helped me be productive far more consistently. I still have bad days where I check my email 150 times. But I've made it to the fifth year of my Ph.D. program, I have three publications to my name, and I usually keep my (new) boss happy. After my doctorate I will not attempt a career in scientific research - the projects are simply too long, and the writing tasks too ubiquitous, for a procrastinator. But I will find something else to do, something with more structure and less writing, and I will probably be okay.
It is hard, but I hope you'll be okay too. Good luck.