You're not alone, sister! I am in this same situation right now, too, with my husband's side of the family.
My two brothers are much older and were gone by the time my memories start, so I lived as an only child.
My husband often doesn't agree with me. But all my life I've observed people from the outside-looking-in, and I swear, I think I see what more of what goes on in both sides of our families without having to be there. So while he likes to think he doesn't agree with my assessment, he has admitted numerous times that I've been right.
And I don't tolerate much. Just because it's family doesn't give a license to treat each other like assholes.