I was looking for an Old Norse word for "psychopomp" (one who guides
the souls of the dead to the afterlife)

So far the best I can come up with is Dauði Fylgja. I'm not sure if I
have gotten anywhere close.

Also I am having issues with pronunciation. for example I have no idea
what the difference between d and ð is.

Can anyone help me? if not for a better word, then maybe on how this
is pronounced?

thanks,

Juan