I'm sorry to hear about this. I'm sorry that your sister decided to "out" you to family & friends. That's just horrible.

I don't understand fetishes that well. I understand mine & that I'm still exploring them, but where they come from.....well I'll leave that to science.
I do know everyone is different & the world of kink & fetishes is a bit mysterious. Luckily we have the Internet to help us realize we're not alone.
And I'd say you're not alone. I've heard about your fetish before & have read about it. So it's different from others. Yes.
But whips & chains can also make others run away too. Many do not understand & are quick to judge.
Stop judging yourself according to others. Live in your skin. Bec no one else fits in it!

Wish you the best.