Despite not having felt physically threatened... the way you're describing this sounds like you might be feeling a bit emotionally traumatized by what you saw (and given how scary it sounds just reading your account, I would definitely think that was a normal response). Do you have someone you could talk to about this face-to-face? I know discussing this sort of thing with another human in person helps me process this kind of emotional upset. Either way, I hope you're able to work through it and feel more centered about the whole experience soon. :(