It does help to have some kind of feedback mechanism in place to have both a reference point for checking things as well as a little pressure to make sure things get done right (in this case to help remove the errors).
The way that programmers do this is to set themselves a mini-project that is modest in its goals, but provides enough of a result so that it can be realized.
What might help you is to have some sort of mathematical project where you could say implement your model and plot it to see if it comes out right. The result of the plot can help you reinforce the results as well as give you feedback on whether you made mistakes in the process.
You'll find that the rewards come from the feedback of your own work, even if it is in little chunks and the great thing is that with computers, you can store all the work, code, simulation results, thoughts and everything else and see it develop over time which is one of the best ways of getting motivated and staying motivated later on.