Mixed on boyfriends family

So my boyfriends family I am mixed on. I love his nieces and his mom. But his older sister talks non stop and never lets us have just us time. She always has us watching her kids while she’s at work. I love his mom, she’s a sweet heart. And his dad is a drunk. And is mentally abusive. Talks about how he wishes he was never born and stuff like that. He’s stuck in this mentally abusive house and right now can’t move out. He can’t live in the city because of his ptsd. And I don’t have enough money to move out in the country like him. Also his grandfather is on hospice and won’t make it through the weekend. My boyfriend was the only one not allowed to see his before he passes. That made me cry because I never got to say good bye to my grandpa before he passed and I know what that’ll be like for him. It’s getting to the point where I won’t want his family except nieces and brother)who’s autistic) younger sister and brother to come. I’m mixed on his older sister and father. I keep my mouth shut sometimes when they get into it. When I go to pick him up because I know if I say something it’ll make his life worse. Any tips? Am I over thinking this to much?