Procrastination is just something you need to learn to deal with. I struggled with it all the way through high school and nothing has changed at uni.
Keep your mind on your goals, break tasks up into little bits rather than imagining one huge chore and don't get down on yourself when you bail out of studying to go do nothing. That just creates a vicious cycle.
The way I got through stuvac last year was, oddly enough, providing myself with loads and loads of distractions, to the point where I could convince myself that I wasn't actually studying. I watched sooo much TV while doing practice papers that I now permanently associate Scrubs with 4U Maths. And it worked
.