I used to feel that way, and it's a legitimate concern. You need to trust that people won't read it to some extent, if they are worthy. I keep mine in my bag with me all the time.
I used to keep a private password protected blog, but I now prefer the paper journal. It's so worth it. Even if you burn it in the end. But it's even better if you hang on to them to be able to track your progress. or just have a record of your life and things you would have forgotten.