Hello I hope I can shed some light on this situation. I am fairly familiar with WILD as it is my favorite induction technique.

That experience of yours as the others have mentioned is not alone. I once experienced the same thing and it scared me for some time. More than likely it is your mind manifesting that fear because you now associate it with falling asleep. Fear not! Its easy to overcome

Basically as the others have mentioned, you need to bring yourself to terms with the fact that it is all in your mind. If you come face to face with these kind of hallucinations again, close your eyes. Just try to go back to sleep and by closing your eyes you are in a way "containing the fear". Now it cannot spread into your visual field so you wont actually think its there in front of you. Instead it may manifest into a dream, in which case you will need dream control Once you simply accept the fact that it is a dream, it is your dream, and no harm can come to you, you will be able to conquer this. Another good way to rid of these terrors in a lucid dream is to close your eyes in the dream and think intently about something that makes you happy, or any other mood than what you are getting from the hallucinations. You can also picture a happy place or anywhere else (this requires more dream control skill though)

I hope these tips help you and once you conquer the fear I doubt it will come back to haunt you. Just keep with it and you will succeed! Do not let this stop you from lucid dreaming!