This reminds me of intrusive thoughts, perhaps in OCD phenomena as well; one example being "what if me thinking this thought kills someone I love"?
Violence statistically is going down, and we always hear about people being killer, yet, we never hear reports of people being
not killed. Think about it:
millions of people,
every day, come home safe, in their homes,
not threatened or endangered or killed; and even more sleep without any threat killing them, going on to wake up the next day, with no killer or burgular bothering them.
I don't think I explained myself very well. I just meant that most people don't really walk around thinking about how fragile everything is. Sometimes I just get this quiet thought that life can stop at any moment.
Guess I meant having the overwhelming anxiety of it all.

I understand that. Feeling our life is fragile is
such a terrifying feeling.
This idea from Epicurus helps me to worry a bit less about death unexpectedly entering upon me:
When we are here, death is not here. When death is here, we are not here.
I mean it in this way. If I'm walking down the street, and somebody nails me in the head with a bullet, I'm probably going to be lights out before I even know what hit me. So, it's not my problem
before it happens,
and it's not my problem
after it happens. So I shouldn't fear, nor care, and just accept that I can do what I can, and maybe that's enough.
I think there
is genuinely a lot we can do, though.
I think it can be good to recall that a lot of causes of death are more slow things, like unhealthy habits that can be changed over time (both physiological and cognitive). A lot of death causes are not instant but slow, and so we have far more control over them than we may realize.
FoxSauce, do you think cognitive behavioural therapy might help with your specific fear on this? I recognise you may have tried it already, but I want to emphasise this just in case it's an available option for you. A lot of these anxieties come from
information or
conclusions about how we believe the way the world works—for example, being scared about being killed if you hear news claiming street killings are common. But I would wager if we came to know of, say, statistics showing street killing rates are
plummeting in modern years, we may very well just feel a bit better about our own safety and very own life :).