Joanna.
Nobody is against you.
What I think occurred was first a voice that stated "I will kill you". As you said.
Not everything with clairaudience is to be taken with absolute literal interpretation.
Next, you had what is called a prophetic dream. A sequence with two individuals whom appeared like those in physical life.
The voice and the dream were simple warnings about the accident.
It was an accident. Both parties your friend driving and the couple who hit you should have stopped and spoken to each other. If anything to check if everyone was alright, and if your friend so desired to speak about damage. That is how adults handle this. I do realize however, it doesn't always work out as such, after all you can not actually force someone to stop. In that case it is good to try and remember or pay attention to the type of vehicle, any license numbers etc.
I believe the dream was simply a warning you were not able to heed because you were not able to interpret it as a warning regarding an accident. This isn't your fault. This happens to many people. Especially with the vague quality of the dreams, its understandable that it was unnoticed.
It may help to pay attention to how you feel more before, during, and after your dreamtime.
I do not believe those who hit you intended to hit you. How young about would you say they were, looked?
That also may be a reason they failed to stop if indeed they failed to. They very likely could have been afraid.
You and your friends, and the drivers in the other vehicle are all lucky you are safe and alive.
The white feathers and coins speak volumes. I believe those are signs. Very profound ones. From the creator. That you are still here. Fresh, young, alive and well. You have not lost either of your friends either, and do not have to deal with the remorse or other feelings associated with anyone dying during this accident.
You have very much to be grateful for.
The voice was not a death message. It was a warning. "I will kill you". It is quite possible it could have been the higher self/aspect of the female individual, warning you herself. Without the actual individual's knowledge if you get what I mean.
It wasn't a death threat. It wasn't literal, in that sense but in another. It is difficult to explain what I mean here.
This could be an indication that you are apt to have clairaudient abilities.
The last voice I heard was but a few moments ago. My mother and I was talking about family health concerns not long before this. As I was relaxing lying down I thought "I am more than liable to have a heart attack".
Incoming voice "You shouldn't be smoking".
I am a cigarette smoker.
So there you have my thoughts on this in particular.
You were and are not in danger of an angel threatening you, but rather you were warned by the creator on a couple of occasions that something life threatening (possibly) was to occur, and you by no fault of your own had trouble with interpreting that. Thank God all involved are safe and well.
The after effect of the white feathers seems to me as a clear indicator of a spirit guide, more than likely an ancestor, the warning too could have been a guidance.
Essentially your alive and safe to be able to ask this question.
Let's celebrate.
Blessings.