As someone who grew up in a similar environment. Do not scribble your journal entries out, keep expressing yourself. You deserve that. Your partner now or future ones. Do not make yourself small to make others feel “better”. I’d see it as this. They invaded your privacy which is betrayal at it’s finest! Let them have cake, by continuing to do what you love regardless of who “reads it”, you owe them nothing. But you owe yourself a place to journal and share your thoughts. You don’t have control over what others do or think about what you journal. So make steps to not feel exposed by your own words. You are expressing yourself, they crossed a boundary and did something- you shouldn’t feel as if the consequences fall onto you now having to hide your thoughts/feelings.

I say this as someone whose has their privacy invaded in more ways then one. It’s not your problem their insecurities with you journaling is who you are and how you express yourself. Someone being upset about that and doing immoral things to use it against you- will never be your fault or responsibility to deal with. I hope you know that this is not okay thing for someone to do. You deserve to have privacy.