“Fun” aunt in the mother’s position

Hey ladies! I am 21 years old and raising my niece and nephew. My niece is 3 and my nephew is 8 months old. They’re my absolute world. But I am struggling with making friends as no one seems to understand the situation. My sister is deep into active addiction. I’ve had my niece since she was 9 months old and got big boy when he was 2 weeks old and they released him from the NICU. She was using during both pregnancies but his was far worse. They’re both happy and healthy children. But it gets lonely and difficult trying to explain to people why I’m taking care of kids I didn’t birth. Ideally I would like for their mother to raise thin because every kid deserves their mom. On the other hand I would love to adopt them. Is there anyone here that can relate? And would be interested in chatting, getting to know one another, and helping each other with tips, tricks, and advise? Or just being an ear to listen when you need to vent?