How do you force yourself to do something that is extremely urgent, extremely important, but for which you have zero motivation?

My disability took a bad turn during finals week and I had to postpone all of my final coursework. I’ve taken all my exams, but all that remains is a single homework and a research paper for this one class. I’ve done the homework (need to format it), but I haven’t even started the research paper. I’m sitting here, knowing that it should’ve been done yesterday, but I literally cannot bring myself to even start it. (I do have really bad pain & brain fog today, but I can’t afford to not work).

Help? Send motivation? What are your best get shit done tactics?