Thank you for this post, it's helped me understand how someone I used to know may have thought and felt and seen things. Here are my thoughts to try and give support with my perspective, feel free to ignore it if it makes no sense for you.

Social events come off quite superficial, especially when we would like to receive deep empathy. Because with social events, people are usually not expected to stop and go deep with things. That will understandably feel insensitive, and like the people are insensitive or uncaring, too.

It also reads to me like you felt really bad because of the cousin getting mentioned and then you didn't feel good about the superficial social events anymore, so they would feel rude and weird and uncomfortable and hurtful and sickening and unsafe and stuff.

Depression, anxiety or trauma can be a lot like that, making things feel that way. That's where special boundaries do have to be set up too, like maybe avoid the scene if your cousin gets brought up (and you did leave).

Others may not understand right away if they never experienced depression or trauma or anything like that. It doesn't mean they are unempathetic, insensitive, dense or mean people. It doesn't mean they can't put themselves in other people's shoes. It does make depression, anxiety, trauma harder to deal with. I'm sorry.

I'm glad your aunts reached out to you to refute the gossip about them being mean, and that your mother helped understand about your uncle's behavior. Your aunts and uncle do not sound like bad, evil, mean people to me. But I don't know your family, I am only talking about the description of this one social event.