Could be the thing you´ve spent so much of your time and self invested in, is going to take as much to entwine out of yourself.
From your limited description, you seem to imply you spent quite a bit of time inviting this thing into you. It teased you by gradual revealing, to get you to invite more and more of it into you, so it would become more real to you; into your imagination, your creative powers, your thought processes, your intellect, and your time and energy, and worst of all, your love and devotion in your heart.
At least, that´s what I get from your snippets of info.
You seem to know now that this thing is a demon (or demons).
Then take it to the next step logically, that the demons are spoken of extensively in the Christian Bible, so it´s to the Bible you must go for the answers. And the demon is only a symptom of the problem you have.

The problem is Who do you want to be your owner? The demon has already made a claim on you, which by your earlier actions, you supported.
Only a complete change of ownership is going to change the situation. Then you know the only way out is total allegiance to Christ.
You seem to be on that path.
With very powerful entities, and very deep intwinement; both prayer and fasting is required.
I would find other Believers to stand with you on this.
And resolve that this will be something you´ll now have to keep on this path...there is no turning back the clock to how things were before you did this pendulum thing...

Beware the quick fix of more garbage like the pendelum...drawing symbols to free yourself is just more of the same...from the same source...The danger of the quick fix is that the symptoms will go...and now you´re spiritually in even deeper, with no danger indicators.

It´s a battle of life, in a battle of your life, that will last all of your life, contesting for your spiritual life

***I am still plagued by doubt as to what it is and what it's intent is, as it does delight in instilling fear What is an unclean spirit? a flawed being much like myself, initially I was terrified of it The spirit's conduct is between it and God, just as my conduct is between me and God, and your conduct is between you and God.***

First things first. You've got a demon inhabiting you. '...a rose by any other name, would smell as sweet...' -- does it really matter if we call it a demon or unclean spirit or bad boojum?
What we are talking about is an entity inhabiting your body with you...if it were a tapeworm, (even if it happened to help you with your diet), you'd take medicine to get rid of it... What are the effects, if not fear, of being in the presence of a demon? Let's see...confusion, doubt, uncertainty, double-mindedness, lying, hating, torture...

You're good at lying, you say...well, you've lied to yourself pretty well over this issue... You know it's a demon, no matter how much you equivocate and rationalize...You even realize the steps necessary to get rid of it...
And this, 'it's between it and God', has been settled 2000 years ago. Between 'you and God' is still ongoing. We ARE talking about it being between 'you and it' -- quit lying to yourself about it...you have a houseguest from hell, and know you should throw it out...I don't care what its manners are...
Make no mistake...the demon believes in God and knows Him well -- it's not a theoretical thing with it...It knows where it stands -- and more importantly -- it knows where you stand...
And it doesn't hate God as we know it. To it, God is a FACT that can't be dealt with. It reserves its emotional hatred towards the things and creatures of the Creator...Especially you and I....And its only avenue to express its nature is to attack the Creator through His works...more specifically, us -- it is most 'satisfied' when it turns beings into creatures like itself, not physically, but spiritually, similar....
...and the tool of its turning is to blind or distort any creature to its relationship to the Creator...
It will allow you any cosmology that keeps you from repentance and return...
The cosmology that speaks of these things, also speaks of the cure...
But first of all...you're lying again...You don't really want to get rid of this thing, it makes you 'special'...

What you really want to get rid of, is the 'negative' aspects of it....
If it was quiet and peaceful and gave you winning lottery numbers, you'd be more than satisfied to keep it... You originally wanted to know the 'future'...the pendulum called up the spirit of Divination -- to give you answers, to know the right choice, to turn over your decision making process of free will, to something else, to choose for you....
Just doing it to be doing it, is another lie to yourself... You wanted power, and you know it...the power to guide your own steps by your own inner sense of direction....And deep down, all humans know that that's folly....All of experience teaches us that...

You're going to object that I'm judging things from my cosmology...true enough, but where do you think the story of the enmity between demons and humans comes from? Wouldn't you think the cosmology that has a handle on what the problem is, would have a notion of what the solution is? I'm not so sure you want that solution...your long equivocation on what constitutes being able to judge things, tells me volumes....
Not to knock your beliefs....But if you're getting no solutions from that avenue, then why hold onto what obviously doesn't work? If you're serious about getting a grip on your problem -- here's step one to understanding how far off you are....

***who am I to pass judgment on any being, ***

I hear that statement, and I know demons are around...

This is a major weapon in their arsonal...(Won't go into the other concept weapons for now, that's for another thread). The battle for spirit and mind begins with how you think about things...and if you think you are not able to judge 'what is of God' and 'what is not', then you've handicapped yourself into paralysis...

We are designed as reasoning, judging, beings...All day, decisions are made -- is this for health, or is this poison -- on every level...Will this person mean pain or respite...Is this person lying or are they truthful...Is this love or enfatuation...do I turn left or do I turn right...We are called to judge constantly...How is it then that people are to be left out of that process?

Good distortion on the enemy's part to take the ONE thing we are not to judge (and this 'judging' is more an extrapolating into the future) -- NOT to judge the ultimate destination of any soul...That is one thing that is totally in the hands of the individual and God...
I can judge a person and say they are evil, but I cannot judge that they will end up in Hell...I can judge that the things they do will certainly contribute to them heading that way...
But as many that will turn towards Him at the last minute, there could be those that lapse too at the end...Only God knows... To judge in regards to outcome is to presume and remove the factor of freewill that can work at any instant -- in rescue or in rejection...

And you wanted to turn this over to a device? How did you think that thing was going to work? A piece of string and a weight has no intrinsic ability to know either about you, or what would be an optimum choice for you....

Picking up a bone and waving it at the sky is not going to cause thunder, so I'm never going to attempt to try it...But if I ever had a notion that I could draw upon some sort of energy symbolically and imbue the bone with that power -- I would try it...in the beginning, just to see...And then habit becomes Incorporated into your being...

You knew that the answers were not in your subconscious...An outside device calls upon outside forces...

***for no human or pseudo expert on God(including priest/minister/whatever) can judge you ***

Doesn't need an 'expert' on God to see what is happening around you. Doesn't need any kind of expert. But only someone with eyes glued shut couldn't see that this is a demon. You abdicated choice-making, and their is no spiritual vacuum that Something won't try and fill...considering we have an active enemy, it's a dead certainty..

So on some level you must have known what you were asking to do...
Perhaps something whispered in your ear, to set your feet in that direction...with no protection and master of your own fate, it's not only possible, it's darn near inevitable...As you're finding out now...

***the difference between the spirit and myself, in my eyes, is only a matter of degrees.***

What utter crap...you and it have nothing in common, you are two different orders of beings...but you should know this too, but don't want to face it, because it has got you identifying with it....

...don't want to justify it with psycho-talk, but I'm sure you've heard of the Stockholm syndrome...

***I do wonder if this whole thing is in response to that***

And you know the answer to that also...you were going to slip out of the enemy's camp...

And for what it's worth to you, I am familiar with this very thing, repeatedly shows up in my life...and you are not so unique as you think you are...in fact, I see you quite clearly...

And you already know what you have to do....