What Have I Done?

I've never seen a person die, take one last breath and close their eyes,
No special effects, all improv lines, no cameras on with film inside,
But I can guess confidently how it will feel when death finds me,
I'll spot the end, see it coming, and hold on tight to what I've been

I let you sink, into the earth,
I am the driver of your hearse

Oh my god, what have I done?