In an earlier post, I encouraged you to write about your experiences with mental illnesses and brain disorders, whether as a mental health consumer or someone who cares about one.
A different project is to keep a daily diary about other aspects of your life. If you are a mental health consumer, you are not defined by your diagnosis. I find it encouraging to keep a record of those things I do daily that have nothing to do with schizophrenia. A downturn in mental health is sometimes overwhelming for the person who lives with it, and those episodes can make up the notes I suggested you keep on your mental illness or brain disorder. I propose that a diary be something distinct from such notes, that you use it to record what are, to you, memorable events outside the scope of your diagnosis.
Some excellent smartphone diary apps exist, but I prefer the old-fashioned handwritten diary. When I look back on my diary entries, I am often pleasantly surprised by what I have accomplished over time.