I used journaling to keep track of my patterns to help me see shifts in mood or behavior. I made myself a template and filled it out every day. I kept track of my meds, diet, exercise, anything going on physically or medically, my activities, shifts in mood, experiences of depression, anxiety, psychosis, racing thoughts, my dreams, etcetera.

I found that I was able to see certain patterns emerge over time and that gave me the ability to plan ahead and have greater influence on my health.

I wasn't worried about anyone reading it and it also helped me have the details needed for better sessions with my T and my pdoc. In theory though it would have been easy for me to keep it someplace private if needed or do the same kind of exercise in an app on my phone.

I hope you're able to make it work or find a way to apply the essence of the concept of journaling in a way that makes sense for you.