Your sister who said that "she would know" if her daughter was being abused is not just insulting you, she's also insulting her parents. She's implying that she's a better mother than your Mom. And yet she is KNOWINGLY hosting a paedophile in her house.

Seriously, the way your family are treating you makes me think that they're very twisted and sick. Do you have any support system other than your family to fall back on? Ideally you need to distance yourself from people who are so toxic to you. Please don't think I'm saying that they're all bad, I don't know them... but I do know from what you've said that there's something very seriously wrong... and it's not you.