its not so much fear of the person as it is associating them as a friend that concerns me.
So, within the dream, you're back in a time when the two of you were friends? And then, when you wake up, you're snapped back into a reality where this isn't true?

I could be way off, but it sounds like, at some level, you're just missing "a simpler time" that you almost wish you could get back to. Your anger at this person couldn't be more justifiable, and I am not saying that you should try to make nice, because that would make me an idiot. It might help your dreams, though, if you could accept whatever hope/wish/fantasy is creating these dreams as something you feel, though not necessarily as something beneficial. (Note: I am not saying that you need to forgive this person, only that it might help to accept your conflicting feelings regarding the situation.)

Note that I'd also accept the advice of a psychologist I've met face to face over some random entity on the internet (me). I'm just making suggestions that might affect your dreams.

As for lucid dreaming, if you think it can help you, absolutely go for it. I've found that lucid dreaming is a great tool in defeating your nightmares. Also, everyone's had one of those "everything is great" dreams where they wake up feeling awful. If you can be semi-aware, or even lucid, during your dreams, then when you meet this person in your dreams, you won't think of him as a friend.

So, my advice? Look for this person/situation as a dream-sign. If you see it, and you can remember that you were looking for it, you'll realize that you're dreaming. At this point, you can escape the dream, or go do something more fun.