Its seems like you know that studying at the last minute is not a great habit and that it needs to be broken as quickly as possible. You have to first recognize all the reasons that procrastinating and being lazy could work against you and your success. Maybe you could think about the things you would enjoy more about your classes or even your free time if you stopped procrastinating and saved all those hours of anxiety that build up while you are procrastinating.

Next, you should try to think about why it is that you are procrastinating the things you are procrastinating. If for example, you never start writing your assigned essays until the last half hour before they are due but yet you do your math homework on time maybe you need to think about why it is that you are really afraid to write essays but love math. If you are getting things done with your current method then maybe you don't need that many changes. The next step is the hardest ----> you just have to try to build up better habits and then keep them up. You might want to start with one thing at a time, beginning with those that are easiest to conquer and can give you the greatest sense of satisfaction. I don't know of any great secrets about building up better habits, I think you just have to follow through with your plans and go step by step. But since I still have secret procrastination problems, I had to consult a friend who is a non-procrastinator.

She says she always does the things she loves right away. In general, her advice is about trying to turn the things you have to do into things you love or at least realizing the things you love and then spending as little time as possible on the things that don't get you that excited. But if you still have to do things that don't make you that excited {like everyone else in the world} then you could try to make these boring tasks more fun. She suggested meeting with friends to work or changing your working environment (moving your desk outside etc.) For her what is important is that she does the things she loves with passion and then it's okay to spend less effort on the dreary tasks as long as they get done. So her secret key is trying not to be too hard on herself for not wanting to do the things she doesn't like while finding the things she loves to do and doing them well.