I worked with an occupational therapist a few years ago because I was having problems coping at university. One of my problems is attention span and motivation, and I'd never get anything done because I couldn't get started, or I'd get distracted, but I figured out I could do something for fifteen minutes, and at the end of fifteen minutes I could either take a break, or go for another fifteen. Splitting it into small pieces like that helped a lot, usually once I started I'd keep going.

Is there a centre for students with disabilities on your campus? I got some accommodations through mine, including extra time on assignments if I spoke with the professor in time.