You have my sympathy, but it sounds like you had a super fucked up childhood and you’re now externalizing that trauma onto an unrelated group of people.
Your uncle was a sexual predator, not a trans woman. Trans people are not usually gender fluid so they don’t switch back and forth like your uncle and they certainly don’t pretend to be a real relative to bully that person’s children!?
Honestly it sounds like your uncle had serious issue with your mother, probably stemming from his own childhood abuse. Abusers are often abused. You don’t mention them, but I’d bet your mothers parents were not great either.