Emotional detachment?

I'm honestly not sure if this is an autism thing, a thing with my family generally, or both.

I'm 24, not living at home any more, and I basically feel like I have no attachment to my family? For example, my brother told me that my mum was getting worried about me since I hadn't called home for a couple of weeks, but honestly, I'm really not that bothered? No one contacts me from home anyway, it's always on me, so I always assume that no news is good news. I have no desire at all to contact them, because nothing ever changes, I can never really talk about anything interesting with any of them - they make it clear that they are NOT interested in anything I like, or it dissolves into an argument - and I feel like I shouldn't say it because you're supposed to care about family, but I'm not sure I really do. Obviously I don't want anything bad to happen, but no more than I don't want anything bad to happen to anyone.

Even my grandma's funeral, I was crying because everyone else was so sad, not because I was. I have fond memories and I keep certain things that remind me of her, but that's it.

I just really feel like I have no connection to them any more. I'm just not sure if it's an autism thing, or if it's just how my family are. Because 2/3 of my brothers are married and moved out and all, and I have barely any contact with them either, nor do I think they have any contact with my parents unless they need something - to borrow some tool from my dad, for mum to pick up a couple of bits at the shop while she's going (one brother is very careful in this current situation, because his wife's sister is quite ill and has 2 young children, so they try to be extra safe so they can help her). The 3rd brother sends me a meme occasionally, that's about it.

I feel guilty because of it sometimes, and especially since one of my housemates is actually pretty close with her family and it seems weird that I'm really not. Part of it might be that I just find contact so difficult - it's really hard for me to just send a message, even if I want to, and none of them really contact me either. And I also find at least half my family incredibly intimidating and scary because of how they've shouted at me/assaulted me/threatened me/otherwise been intimidating towards me over the years, which obviously is not going to help regarding those family members.

I really just can't tell if it's an autism thing, a my family thing, or both, and that's bothering me. Thoughts?