update (just trying to combine my posts into 1 thread and explain my f*** ups)

This is a theory based on my own experience and the research I've done to understand what happened to me. You might need to dig in a little if these concepts are new to you.

Jung, a famous Swiss psychiatrist, spent a great deal of time working to break down the mind and our patterns of conscious and subconscious experience. I came across his work years before I became ill while studying esoteric philosophies. I went back to it recently. Mind blown.

In his work he describes archetypes, or aspects of our experience. There are 4 main ones and many other that represent specific roles we play throughout our lives. The aspects are dominated by either our conscious or subconscious mind.

'Jung believed these archetypes contain elements of our personality that we need to address in order to develop a healthy rounded personality. He suggested that by working through these archetypes, we can begin to choose our actions rather than responding automatically from patterns in our personalities that no longer serve us.'

One of the 4 archetypes is the Shadow.
'Jung felt that the personal qualities we deny, repress or ignore do not go away but are relegated to the unconscious. Here they become personified as the Shadow. This archetype is often described as the darker side of the psyche, representing wildness, chaos, and the unknown.

We may repress our desires or qualities because they were frowned upon by others or to protect ourselves from emotional or even physical harm. For example, a child may learn to repress strong emotions such as rage or grief because they are afraid these emotions may severely distress another family member.

When we later need these repressed qualities, the Shadow may begin to show up in our dreams. It might appear as a snake, a monster, a demon, a dragon, or some other dark or wild figure.'

So essentially when we fear something or experience trauma and do not deal with it we dissociate from it consciously, but it is still a part of us. Jung speaks at length about this process and the extreme effects it can cause when we push these aspects away to such an extent we personify them and they begin to bleed over into our waking or conscious experience. He says this can lead to psychosis and hallucinations.

In my case this is a likely explanation for what happened to me. Before I got sick I was purposely seeking to integrate my shadow to become more whole. In doing so, I accidentally triggered memories of a trauma that happened when I was a child and I completely lost touch with reality. I was awake and hallucinating, but the hallucinations were very symbolic and dream like even tough I could 'feel' them.

I feel it is highly likely the same is occuring for you. You have been unstable mood wise for some time. Additionally, you are incredibly scared to contract the virus and experiencing extreme anxiety. You are hyperfocused on it. You are convinced your parents will give it to you if you visit and they keep asking you to come over even though you're uncomfortable with it. This makes you angry and you repress it instead of telling them the truth of what you're going through and your beliefs. You push down your anger the same way you do about your sister and how they treat her. This is what I was trying to explain a few weeks back when you were so angry and said there was no cause. Your shadow would disagree. There is a huge cause and you are very angry even if you do not consciously identify with it. I didn't think I was angry either, but my shadow came forward and apparently I was furious I had been abused. I digress, but perhaps this helps you see the pattern.

I feel the dark presence you percieve is the shadow personified. It is your fear in form. It is no coincidence it is worse in the dark. Night and the dark are a classic dream symbol for the unconscious. Day and the light represent the conscious mind. My experience carried the same pattern. In essence, your subconscious is in pain and doesn't like being pushed down over. It is trying to get your attention and is asking you to deal with your fear in a healthier way...

There are tons of resources to work with if you want to know more. This article is a good introduction and the source of the quotes above.
The 4 Jungian Archetypes and Why They Matter in Your Personal and Spiritual Evolution – Learning Mind

How did the Klonopin work out and did you call your doc?

And I left this out of my ressponse above, but... The reason you can literally feel the presence is because the source of it is you. Have you ever closed your eyes and remembered something and felt like you were transported back? Maybe you could smell the smells or feel the feelings again or whatever. Our brain is integrated tightly with our sensory perception. When we believe something is real, our senses process it in such a way that the belief is validated. That's why hallucinations and delusions are so hard to come to grips with. Our entire bodies believe them. This is the basis of how virtual reality works. Once the mind forgets you're just watching a picture, you start to fully integrate with the experience. In your case it happens instantly and on a deeper level because you believe the source is external.