My mind is racing like what if you ending up homeless and the 31yr old took you in? My mind is going everywhere with this.

Your Aunt understands that there was grooming happening and a 31yr old knows better than a 18yr old. Also if you knew you slept with your gf’s niece why would you get back together with gf. It’s weird to me. Also the family shunning you is ridiculous. That’s why a lot young people get into relationships with older guys. Family is suppose to protect each other.