A lot of my problems seem to come from mental fabrications. I.e. too much thinking.
I keep reminding myself of this when things get dark during the unpleasant process of purification. This is not an intellectual matter. I cannot think my way out of this. I still my way out of this.
What's needed now is to stop paying attention to thoughts, to the mood, and practise single pointed attention on a meditation object instead. Not too tight a focus and not too loose, a gentle focus that can comfortably stay centred with the object of meditation without straining the mind.
At first one has to endure the taints, the greed, aversion, dullness, restlessness, scepticism (aka the five hindrances). Through it all, sit as upright and still as possible, like the Buddha under the Bodhi tree. Without judging anything that is happening, just mindful and bringing attention back to the meditation object and keeping it there, doing this over and over, calming the body, steadying the mind.
I use different meditation objects at different times, sometimes its the breath, other times space, other times the body, the life energy (kundalini), the emotion of metta, the perception of light, warmth, cold, a primary colour, a sound, a mantra, one of the four primary elements, there's many different meditation objects, whatever meditation object feels like a good fit at the time and holds my interest.
After a time, the composure deepens and the senses start to settle and calm down, the thoughts fade, dissolve,and the mind becomes more and more centred, more composed and unified around the meditation object, and then secluded from the five hindrances one drops into a pleasant serenity, and this connects one with a deeper part of being, a safe place below the surface level of thoughts. Like an inner refuge.
It involves patience at first. One has to endure the five hindrances, endure the taints, the impurities of the mind, the longing, aversion, and delusion, the crazy thoughts, let them be, and just sit as still as possible, anchoring attention with the meditation object. It can take more than one sitting sometimes before it reaches serenity.
I did have a powerful meditation experience though which encouraged me to keep at this. Where I reached such a state of stillness and composure that afterwards the darkness was gone, and I was in a completely different mood, like I was glowing. It showed me that this is indeed the way out of the dark night. Stillness, samhadi and equanimity.