I was like this as well - still am to some extent.
I was always academic at school and was able to get away with decent marks without putting too much effort in.
I got in to a decent uni and that plan wasn't going to work anymore, but I still carried on down that route. I could just sit there in my room for hours on end staring at the wall or something rather than doing work.
In the end I found a way that sort of worked for me, and that was to work with other people. Go down to the library together, ask each other questions, discuss topics etc.
Working on my own I just got absolutely nothing done, but working with others I was much more productive.
I discovered this a little too late to really help me though and came out with a 2.2.
Since then I've found that I really get on with the office environment, a dedicated place to work with people that you can bat ideas off and discuss concepts and problems really works for me and I get so much more done in that sort of environment it's untrue. Even nowadays I struggle to get motivation when working from home though.
Make sure you talk to your lecturers as well, they can be a big help. It was something I never did. I was always the guy who turned up for lectures and then disappeared until the next lecture (or sometimes the lecture 3 or 4 afterwards
) Other than a few problem classes I don't think I ever actually spoke to any of my lecturers during the whole 3 years and it's something I reckon really would have helped.