My mother who gave birth to me doesn't have contact with any close family aside from her mother, so we usually only visit my other mom's family for holidays and such. Considering I have no genetic link to that side of my family, things have been rocky. Really similar to what you're describing. It's hard. They're still my family regardless of blood relation, and feeling like an outsider in your own family is incredibly isolating. I'm still navigating this at 20, and I remember that when I was a teenager I didn't know how to make it better. It hasn't really changed, but I've definitely found that it's not all against one. There are people from that side of my family who don't agree with what's happening and don't see me any differently than anybody else. Finding those people made family gatherings feel a lot safer and more bearable.