Keeping personal journal to learn about flares

I was diagnosed with SLE in June 2024 and have been taking hydroxychloroquine since then. It seems to be working. However I am having a flare now and don't know what caused it. Is it possible to figure it out? For that goa;, I'd like to keep a journal. Is there a form that people have successfully used or should I create my own in Excel? Thank you.