Hi Kate. Sorry I’m late to the conversation. I think Debi is right. Sounds like you are having out of body experiences. There are different planes you may be visiting. The lower astral plane is where the lower vibrational entities are said to be. You can probably find information on this here somewhere. My thoughts on the shadow beings are that they are some type of entity that are attracted to certain people for some reason. Perhaps certain gifted people have a higher vibration that allows paranormal gifts, this may attract their attention. What they want is the big question and nobody has an answer. I personally think they are not omens but are there for some self serving purpose.
Thanks for sharing your experience.