Our situations are a bit different, so I'm not sure how much you can glean from my experiences because it's sort of like I was acting under the unusual - yet consistent - set of DMT "physics". Through lots of experimentation, I've become quite familiar with how this particular experience goes for me, but there are obviously lots of questions I still have unanswered. One is why I am sometimes targeted by these negative entities/energies when I feel I've done nothing wrong. I can't explain their spontaneous and seemingly arbitrary appearances, but when they come along, I've developed strategies that relates to the ways energy (of which both the entities, objects, and landscapes of hyperspace seem to be composed of) can be manipulated in hyperspace to help overcome the situation.
I have 3 basic approaches, each with their own ups and downs. One is the good ole letting go routine. This approach I've found to be a bit risky; it's like rolling the dice. If it goes well though, it can go really well. I recall one experience a long time ago where I was faced with this seething dark DMT object. I mean the room got really hot. I patiently just stared it down, just waiting out the situation, and towards the end, it ended up blossoming and fanning out into precious and subtle purple holograms spiraling out with loving energy. In my case, it's a crap-shoot, cause sometimes just sitting still is like just staring down a rattle snake hoping it will go away.
In your case, part of dealing with your Nigredo can involve accepting the unpleasant emotions and mind states you have as a necessary part of the alchemical process. They will make the spiritual gold shine all the brighter, and the more negative energy there is, the more energy is available to be transduced into positive energy.
My second approach involves the manipulation of attention. In a nutshell, I've discovered through my experimentation that the old Buddhist saying is true that 'where the attention goes, energy follows'. As has been aforementioned, I find the entities of hyperspace to be composed of energy, and so by averting my attention from them (though they sort of attract your attention in their visual non-uniformity with the scene) it has in some cases prevented the entities from making their way over to me, or in a way robbed them of the power that they would be augmenting by my paying attention to it. In
DMT and Attention (Negative Entity Mitigation) I describe in detail how I reached my conclusions. If you want to try and apply this to working with your Nigredo you might want to consider that although you may have aversive reactions to your unpleasant feelings, that it may be necessary to dwell on them considerably in order to devote the proper attention and energy that they need in order to transform themselves.
All three of these methods that I'm talking about involve the manipulation of energy. Hyperspace is synesthetically bound, and so one kind of frequency can affect one up to all of the other kinds of frequencies involved. It appears to me to be entirely frequency-based. There are visual frequencies (colors), audio freuencies (pitches), tactile frequencies (buzzing) and then the sort of frequency of the aether in which the whole experience rests. If you can alter the frequencies going on in the experience, you can alter the experience. I thought of this analogy the other day: it's sort of like as if you had this robot, and the robot executed its own commands via a chip that was emitting certain radio frequencies to parts of its circuitry involving motion among other parameters. Well if you managed to get a remote control that altered the frequencies the robot was receiving, then you would modulate its activity. In the same way, I can use the sound of my voice (and specific sounds at that) in order to affect the energies that are these negative entities since one form of frequency (my audio frequencies) will affect the audio frequencies that they are emitting in order to carry out their hyperspatial activity. It's a funny analogy now that I think of it because sometimes when the DMT energy interacts with the body's limbs, it can autonomously move them as if you are the robot, and they are modifying your neuro-electrical "commands". You can check out more about it
Unraveling Negative Entities (scroll down to post #9...#9...#9...#9...to see an accompanying illustration that actually depicts the alchemical process a hand). I have found this particular method of sound energy manipulation to be the most reliable in defending myself. Hope that all makes sense! Go figure how you can apply this one to your Nigredo other than taking up some holy singing or something of the sort. Don't forget that shamans use their icaros (ayahuasca songs channeled from hyperspace) in order to navigate the experience.
"Science without religion is lame. Religion without science is blind" - Albert Einstein
"The Mighty One appears, the horizon shines. Atum appears on the smell of his censing, the Sunshine- god has risen in the sky, the Mansion of the pyramidion is in joy and all its inmates are assembled, a voice calls out within the shrine, shouting reverberates around the Netherworld." - Egyptian Book of the Dead
"Man fears time, but time fears the Pyramids" - 9th century Arab proverb