Where do I “fit” , How to come out

Hi. I’ve been finding things about myself lately (I’m 24). I grew up in a very homophobic household so when I was younger I never “entertained” the idea of possibly being in the lgbtq+ community. However, I’ve been doing some self research and research on terms and such. I’ve come to the realization that I am demisexual but also bi or pan possibly ? I know people have different definitions on what bi can stand for. If I’m attracted to non binary people would that make me pan?

My sister came out to me last year. And I would like to tell her this and ask her, however, I’m scared she won’t necessarily “believe me” as I’ve identified as straight my whole life.

Please no mean comments 🥺