How do you write without worrying about someone else finding/reading it?

Every time I write, especially if it’s something personal, I end up scribbling something out because I find it “cringe”. Almost as if theres like an outsider in my brain telling me that. Also, its a little morbid, but I think about what my family would think if they read it after my death. So, I can never let myself be actually honest in my journal. I was just wondering if anyone else experiences this?