Hi,
I wouldnāt panic just yet. Your experience could have been, as a previous reply suggested, just one of those āhorrible nightmaresā that seem really real. I say this because you were obviously very aware that you felt āspiritually weakā prior to trying to sleep. This could have percolated into your subconscious thoughts upon falling asleep/approaching sleep. Also, and please do not interpret this as offensive in any way, I am obviously unaware of your medical history. Please forgive me for asking, but have you ever been subject to hallucinations in the past? If you have, then I would suggest seeing your doctor. If you have not, I would suggest praying the Rosary and Saint Michael prayer or Chaplet of Saint Michael and discussing the issue with your priest as soon as possible if things donāt improve. You are in my prayers.
God bless