Evaluate how successful or unsuccessful your studying has been on a daily or weekly basis. If so, reward yourself immediately. You might even make a list of five to ten rewards to choose from. . Finally, until you have lived with your schedule for several weeks, don't hesitate to revise it. You may need to allow more time for biology, for example, and less for some other course.
Some classes require nightly work to be successful.
Id those classes and build them into your nightly schedule. If you are trying to study regularly for the first time and are feeling burned out, you probably have set your initial goals too high. Don't let failure cause you to despair and abandon the program. Accept your limitations and revise your schedule so that you are studying only 15 to 20 minutes more each evening than you are used to. The point is to identify a regular schedule with which you can achieve some success.