Salaam, this is just something that I felt was very beneficial for me, and may or may not work for others but does for me...If you have a problem, and constantly think about it, and espescially if it's the kind of problem where for some reason, you can't think of a solution just yet, write the problem down. Then you can also, write, down in a systematic format, what you can do and when step by step to sove the problem. You can give yourself dates, as to when you want to accomplish what. Until, the date comes, don't allow yourself to dwell on the problem, tell yourself, you've already set a date to think about it, so it will be taken care of insh'Allah. Just the process of writing down the problem, and why it bothers you helps you to forget about it, because you've written down what's bothering you, and you've written the end-points(meaning what can and can't be done).It also helps you pinpoint what exactly is bothering you, and why it's bothering you, rather than you feeling a certain way, and not exactly sure why. This way, instead of letting those thoughts wander around in your mind, you know you've already written a well-formulated summary of your thoughts, therefore, there's no point in thinking about it again. By the way, this tip was meant for all types of problems, whether it be a school problem, or a personal problem, etc.