If I were you I would write a story about you fixing these problems. Learn to day dream about yourself and what you want instead of other people in books.

Find something small to carry around with you to remind you of what you want. A pretty colored rock, a special piece of jewelry, some "talisman"/touchstone.

Remind yourself your body is what carries you around and makes sure you can do the work and not get tired, dizzy, lose concentration. Keep fruit and nuts, easy things around to grab the moment you realize it has been 4-6 hours since you have eaten something. Invent a snack you like with protein, vitamins and minerals (I have a runny, natural peanut butter and use it as dipping sauce for apple slices).

Slowly, deliberately, turn your laptop into something that helps you with your school work, pose questions about your work and do a "scavenger hunt" for answers. Ask questions and write paragraphs in reply; write stories about the questions (or write stories where the questions are asked or the facts are part of the story, etc.; have a main character like yourself who keeps talking about random information (what you are studying) and then the information saves the day, is the answer to the story problem.