This started when I was about 8 I think (I'm 14)

The only thing I can think of...
My parents used to argue in the kitchen a lot. In front of the fridge. They'd slam the fridge door and stuff. They got divorced but it LITERALLY did not affect me at all. I didn't even care. Their arguing didn't affect me either. At all. Seriously. So this doesn't seem likely but it's all I could think of for why I'd be afraid of them