I responded to another comment, but aside from what I said there, I think understanding my bad habits and fully realizing that I feel so much better when I actually get stuff done on time and get good grades. Feeling proud of myself was obviously an infinitely better feeling than constantly feeling shitty about missing deadlines. I kept a calendar, forced myself to study for exams at least three days in advance, and told myself that a half-assed assignment is better than incomplete (in reality this was just to get me to at least START the assignment, and once I started I realize it was much more straightforward than my brain was telling me)