I'm a Time Lord, I travel through both Time and Space. I've been to the beginning of creation and the end of the universe, and practically everywhere in between. I've met demons, gods, vampires, minotaurs, werewolves, ghosts, all sorts of races and beings, and they could all be explained in terms of science and technology, without exception.
So, you may call yourself and angel, and strongly believe that you are an angel, but what I see is that you're a race of being that has been endowed with extraordinary powers, which taken as a whole, resemble what humans on Earth have called 'angels'. I've seen it before, and I've been guilty of doing the same thing, going to a primitive people and showing off my technology to scare or impress them, though I do it mostly to get out of trouble, and I never perpetuate the lie. But other beings have.
Not that I'm saying you do, or your people have. Then again, maybe I'm wrong? I don't know you well enough, or who or even what you are yet to draw any conclusions.