Drama with my boyfriend’s family

Thank you all in advance for reading this. I just don’t know what to do. I’ve been with my boyfriend for 8 years and his family has always hated me. It started when we were first dating, I got uninvited to the joint birthday party that they were having for him and his sister. They just straight up asked me not to come, and my boyfriend was ok with that. Then his sister started with manipulation, telling me the only reason I get invited to anything at all was so he was sure to show up. She started calling me stupid, ugly, and a bitch whenever she was around. It really messed with how I viewed myself, and telling my boyfriend did nothing. When I stood up to her, she told her mother, who joined in on the insults. Sometimes even in front of my boyfriend. He never stood up for me. The weirdest thing is that the sister is always acting like we’re friends. She’ll say we need to do things together, make/buy me things... I don’t get it. But then she tells me I just have to meet her new boyfriend and she’s really excited and I get there and she introduces me as “her kinda friend but not really.” She asked me to be the maid of honor at her wedding recently, and I was afraid to say no because I thought her family would get mad. So I say yes, she treats me like she doesn’t want me there the whole time making me super uncomfortable until it was just the two of us and she was super nice again. The photographer took a bunch of pictures of us together and everything. Then she posts all the pictures of the wedding with me cropped out, and a picture that says “the whole family” with me no where in it. My boyfriend just says “I know, I’m really sorry she’s like that” with no help until recently when I told him that I feel like this is getting in the way of our relationship. Now he wants to go to his sister and mom and say that they’re making me uncomfortable. I don’t see that ending well at all. I feel it’s going to make everything much much worse and might make more of the family mad at me. But he’s determined that that’s what we need to do. He’s a good guy, he’s always so kind, takes care of me, helps around the apartment and everything. I feel like I hit the jackpot, honestly. But he just can’t seem to ever stand up for me. This is getting to me so badly that I won’t go to anymore family events, I won’t answer the sisters texts unless I have to, I’ve completely cut off that family... so can I even date someone if I’m not apart of their family? This is so long I know, I just feel like I’m one step away from breaking up with a guy that’s amazing in every other regard... I just can’t take it anymore and it’s eating me up...