Alright, just to summarize through my mappy lens and reframe a bit, you report that you had lots of powerful concentration, tingling, rapture, bright lights during sleep, and what you thought might be Fruitions but not sure, then all that faded, now you are searching around exploring trying to find something and feeling that part of the problem is the community, teachings, your sangha, and the way the dharma has been transmitted is inadequate and that is where the problem resides. You feel that there are secrets hidden from you behind a curtain. You feel abandoned by teachers and awakened ones. You feel cut off. You feel isolated. You are experiencing much frustration. You feel dissonance and are now attacking what you believe to be the problem. You believe that somehow what you call the preparatory practices as you understand them are inadequate to the task. You feel called to some universal dharma that you yet feel is elusive, so you then start writing long posts about how the problem is with the DhO and those on it in some moderately grandiose way, in the style of Martin Luther, who was also moderately grandiose. I reflect those things but not in any mean way, just describing what is going on. Plenty of us have been in similar modes and reacted similar ways.
Said another way reflecting my quick internal summary of the process, which, done over the internet and by forum posting is not always perfectly accurate, but still: yet another ernest meditator crossed the A&P and into the Dark Night, is now trying to figure out Equanimity, looking outward critically rather than inward inquisitively, as is common. They have inadequate concentration and likely not sufficient practice environment such as a retreat, inadequate contact with sufficiently wise companions on the path or inability to believe that simple techniques could yield profound results, not yet quite to the point of just facing the insights into suffering revealed by insight practice in their own heart-body-mind-space, and are still projecting this outwards rather than just seeing moment to moment the clear and unpleasant sensate experiences of frustration, wanting, paranoia, searching, looking, discontent, restlessness, irritability, blame, projection, and the rest, all of which are normal Dark Night phenomena that nearly all of us who have crossed the A&P are very familiar with and had to learn to deal with in our owh heart-body-mind-spaces.
In short, I might suggest looking to the sensations that make up the core processes you are struggling with, those listed above, and add to the list of sensations to investigate things like anger, sadness, fear, bitterness, criticism, wanting, noticing when attention moves in or out, noticing the sensations that make up the urges to blame others for the sensations in one's body, noticing urges to blame the dharma for the sensations in one's body, noticing the motion of attraction and aversion to deep feelings in one's body, and just proceeding with those deep, profound, subtle investigations, turing the process inward to make those clear, all while also maintaining some sense that there is space around phenomena.
Sometimes proceeding eyes open yet with attention turned into the sensations in the stomach, chest, neck and middle of the head can be helpful, as going into the dark stuff with eyes closed makes some people lose perspective at times, though others do well with it, and you have to figure out which is best for you at each moment. It is hard in the Dark Night to turn the awareness back on ourselves, and easy to react outwardly on jobs, partners, teachers, friends, communities, teachings, society, and a whole host of other entities we somehow become convinced are the real problem, and we can easily miss that this might simply be a normal stage of meditative development and an opportunity to bring the simple, clear light of awareness to aspects of our own experience.
Truly, I know of no higher or more profound teaching than the Six Sense Doors and the Three Characteristics. I have been behind many curtains for "secret teachings", and none are more profound than this one. This was that simple framework that I found most powerful for insight practices. It just requires honesty, subtlety, bravery, and perseverence. Mara's Armies await. When they attack, avoid lashing out at others. Instead, investigate within your fathom-long body. This is the teaching of the Buddha. This is the way of the Dharma. This is what has been practiced well by the Sangha.
Might check out
this video. Might also do a lot of metta practice and the other three Brahma-viharas, starting with really feeling each of those in your own body carefully before moving outward. Don't underestimate these "preparatory practices". As plenty of my Tibetan Buddhist friends have said, if people really did the "preliminaries" properly and as they were designed to be done, they wouldn't need any of the more "advanced practices". The same is true of these practices here.
Best wishes in your practice,
Daniel
PS For those unfamilar with arcane units of measure, a fathom is equivalent to two yards, and thus is about the length of a person, in general terms.