It seems to me that even this question asked on The Question is one of the ways to shirk work. In general, this is called procrastination. For example, I like to allocate time, schedule training and the like. As a rule, nothing goes beyond planning. You just need to pick up and start learning, it's not that hard. I don’t know about the author, but my problem is that I cannot exactly start, as if the volume of work scares me, so much so that I prefer not to take on it at all. Decide what is more important, take an exam or, for example, watch a movie; not to fly out of university or update the feed in search of new memes? The answer, as it were, is obvious.
In general, I advise you to prioritize correctly.
I also have this problem from time to time, but I have my own life hacks. First, find motivation (this sounds very abstract, yes), that is, understand how it will be useful for you. But this component alone is not enough, so find interest for yourself in this (some topic, section, personalities, for example). Do not limit yourself only to textbooks, anyway, you cannot remember most of the knowledge presented there, so watch films, find channels on YouTube, resources (like PostNauka or Arzamas).
Maybe you didn't manage to learn how to build your educational activities on your own. There seems to be a desire, but you don't know where to start, where to find the material you need, how to analyze it, structure it, how to organize your workspace.
To do this, you just need to see how the same teacher works when he starts studying a question, or when he just goes about his usual business. You need to ask him for advice on what literature is better to read, how to work with the information received, how you can save time (for example, read sources on a topic of interest in a condensed version, in the form of diagrams). Try to learn how to take notes, record your own thoughts in the form of notes. It is also important to make a plan for your work and follow it, ticking off the completed tasks.
Another reason may lie in the fact that you yourself are not sufficiently motivated in this activity, that you are forced to study something from the outside, and you would like to study other issues. If so, then you should do what you personally are interested in and you see profit in it. Interest is the best motivator.
And it is so important to learn to find positive in the study of any issue. Studying is always development, movement forward, valuable experience. And even not so much knowledge is valuable as those skills, personal qualities that you develop in yourself.
Study with your favorite music, share your knowledge with people, find and read new interesting books on the topic, and you will certainly succeed.