Jimbo03,
It is completely normal. Almost everyone has these kinds of experiences. I certainly have.
Stress release is not a clean, linear process. Instead, it's a little like cleaning out a filthy basement. As you remove old boxes and barrels, you discover new layers of filth that you never suspected were there.
Some meditation sessions seem the same, perhaps for days at a time. Other sessions seem wildly different. All this unpredictable and random variation is a necessary result of this natural process. Our brains are not computers, operating by perfectly logical and deterministic algorithms; they are extremely complex, extremely interconnected dense masses of packed neurons, interchanging signals massively in parallel, not only along and through axons, synapses, and dendrites, but indeed over three hundred or more active sites on each of their cell bodies as well.
The dysfunctions caused by sensory and perceptual overload (see
http://www.nsrusa.org/about-stress.php for details) are just as complex as memory, deductive thought, physiological homeostasis, visual processing, or any other of our amazing brain functions. Dysfunction and function are mixed together, seemingly at random, as unfathomable by our own consciousness as by the most advanced scientific investigation or conjecture.
The net result of all this messy complexity is equally messy complexity in our experiences. As you write, one day nothing will seem to happen in our meditation (either because the nervous system needs to stabilize a bit before it's ready to tackle more stresses or because the stresses being released don't produce any unusual side effects) and the next, we will have dramatic, transformative, or enjoyable experiences (which may the result either of very different kinds of stresses being released that day or a situation where we "slip past" the blockages and experience a deeper dive than usual).
Another part of the story is that ideally we should all be doing a little bit more than just meditating for 15 minutes twice a day. It is true that doing that is sufficient to release stress, gain more conscious use of our brain, and gradually outgrow the problems caused by our ego. But the ideal path would also include attending an NSR Residence Course every few months or so to have the experience of restful alertness extended over several days or a week. If we all could do that, we would get through the "boluses" of more intense or extended stress release more quickly and more comfortably.
That all being said, a private consultation by phone can also be quite helpful, even in the absence of Residence Courses.
Another point you raise is forcing yourself to be happy or to stop overanalyzing. Neither of these should be needed in a normal life, one lived fully, without the limitations caused by stored stress. It may help to know that whenever you feel that nothing is happening, or that you are having "normal" or problem-solving thoughts, the stress is leaving forever. Any particular stress won't return once it's completely gone.
This should help us regard each session as useful, even those where nothing seems to be happening. The "nothing" is an illusion caused by the perfect balance of the peacefulness of the inner dive and the utter chaos and unavoidable pain inherent in dissolving the stress.
So, whether we experience "nothing" (a dynamic balance), "something wonderful" (an unobstructed dive within), or "being absorbed in suffering" (the release of an unusually deep or intense stress), we are accomplishing the maximum that can be accomplished at that time. That is why we say that in transcending, everything that happens, happens for the good.
It's fine to look back over your experiences and analyze. Just keep in mind that stress release must by definition be messy and that our goal is a life permanently free of messiness, based on strong and complete functioning of the brain and the entire nervous system, free from the distracting thoughts that originate in stress, fully able to act in such a way that our needs and desires are quickly and easily fulfilled.
David Spector
NSR Meditation/USA