It was a documentary about ayahuasca that gave me the idea, but it is a hell of a drug, with much vomiting.
And with much trauma for you to try to survive. Some people come out more wounded than "healed".
BTW, I am doing this because I've been stuck about something for the longest time (15 years) and nothing has worked. But re-watching 'Insidious', 'Poltergeist 2' and the above documentary has reaffirmed a notion that I am haunted in some way. Some part of me seems to have wandered off and been replaced by an unwelcome visitor. The only thing that shifts it for a couple of days is half a bottle of Jack Daniels, but it always comes back.
Don't get me wrong in anything I'm about to say, because fantasy's an important part of us. But it happens in the body and the body's the guide to help find your way in it. If you dim your contact with your own body, whether with booze to numb yourself or using hallucinogens to smash to pieces your ability to sort things while a deluge of psychic content goes berserk, then you really have no guide to help. The shaman will say that's her, but she is not your own bodily awareness which is the ultimate authority in a matter of this sort (so don't bludgeon it).
Just strikes me in what you've said that more dissociation is not what you need. All your experience is your body-in-environment. Notice that even getting this fantasy of spirit invasion ("haunted") that you draped over your bodily feelings ("some part of me") came from your environment (you immerse in much screen-time while also otherwise artificially sustaining unawareness of the bodily self). There's no "bad spirit" to cast out here; too much life has been cast out already.
In place of my prior suggestion of lying down and setting up an imaginary scene to invite your “power animal” to, why not set up two chairs across from one another and sit in one and invite the conflicted bit of your self into the other chair and talk it out and reach a mutually respectful understanding?
Or do it lying down with eyes closed if that makes it feel more real. Though I think it doesn't really make anything feel more real. I’m a skilled visualizer but I don’t feel deep trance states make things “more real”. I think that lends to an increased disembodied feeling which is why you get pagans, shamans, et al, going on about OBE’s and possessions and similar, though we experience nothing outside of our own bodily selves, ever. I'm not limiting "self" to "brain" because if you pay attention to both your joys and sorrows and missing bits you find where the phenomena really are... in the tensions and releases of the muscles and viscera of the body.
Thinking it through and trying to use only reason to solve things isn't going to help either. That's dissociation too.
A therapist who uses the imagination (without ever losing sight of the body’s significance in everything) would be the guide you probably should be seeking. Gestalt therapy is where I learned about dialoguing of self to self to resolve inner conflicts. Here’s a sample of the chair technique in Gestalt Therapy:
http://www.cetuesday.com/empty-chair-gestalt-technique/
