I achieved 4 As at A-Level, and I absolutely cannot revise. I'm very easily distracted, and revison was impossible to do at home, so, however much I didn't want to, I dragged myself off to the library every day and stayed there from 9am-5pm to revise. I didn't have the home distractions like tv and music, so the only thing I could do was revise! It gets better once you really get into it, and once I stsrt revising I feel more determined to finish and do more. I think it's also key that you don't bog yourself down too much with it - I did about 20 minutes worth of proper revision and then listened to my ipod for about 5 minutes or something and then started again, it's always better to take breaks rather than revising straight for an hour so you become so bored you don't take anything in. Good luck!