Your handbook can be a physical notebook or a digital one, but the important thing is how you make the entries. You don't want to list solutions under a header of "bad day" because that's generic and pretty much encompasses everything. Instead, try to describe how you feel. Use descriptions that you'll understand. They do no need to make sense to anyone else. "Unmotivated and lethargic" may be how you'd communicate how you feel to someone else, but "unmotivated, don't even want to feel better, chest discomfort, and sugar cravings" is an example of a more descriptive and personally accurate set of symptoms.
Putting together the handbook is going to take some time and effort, but when you're not feeling good it will give you something easy to do. Sometimes the worst thing about having a bad day is that it seems to just get worse since you can't motivate yourself to do anything. Chances are you can motivate yourself to eat, sleep, listen to music, play a game, watch TV, or do one of the many things that could shift you into a better state of mind. If you don't succeed, then you've learned something about what works with that particular situation. With a little work and some patience, you'll eventually have an entire personal handbook full of answers to all your problems.
show you how to incorporate sketchnoting techniques into your note-taking process — regardless of your artistic abilities — to help you better process the information that you are hearing and seeing through drawing, and to actually have fun taking notes.