I just wrote my first erotica story
That's very interesting. What inspired you to write erotic stories?
I feel my sexual fetish isn't getting satisfied in my normal life
Congratulations on finishing your first story! It's okay to write erotic stories to live out your fetishes on paper.
Never know what next year has in store for us if my story is popular. But maybe I'll end up hurting my own family if they find out.
You're right that your family might be embarrassed if they find out that you wrote a popular erotic fiction, but if it really is a success, I'm sure they'll be proud.  There is nothing to be ashamed of, and even if they disagree, you can just tell them that you were writing about innocent fantasies.