There is much material upon the subject. It is not unusual to feel as if one is loosing their grip on reality when coming into contact with truths, somewhat of a hard-reset followed by a re-format with a large update to the OS, it makes complete sence that in this process one feels as if theyve lost a form of protective layering and is suddenly being bombarded with gamma rays of information. What makes it seem unusual is as you say 'once it begins it moves rather hastily', the speed at which the information alters your view can be startling.
You may assert that this is very much a requirement for the process, how else would one be made aware that they are transforming/trancending old lines of thought and onto a broader network, the alarming factor is simply the contrast percieved between the remnants and the new vision whilst they transit from one to the other. One requires the will to seek along with the intent to know more, once this is achieved the rest runs like clockwork, those whom are as yet to set themselves upon this path will initially envoke the idea that 'why is this not happening to everyone else, and at the same rate?'. All are on the path so to speak, though you may see yourself as having 'stepped up a few notches', the gears of universal motabalism, think of it as a realisation that keyed you into catalysation.
An emotional rollercoaster is to be expected, and with that said one should be wary of expectations, they have a way of making new developments seem like alarming experiences, which adds to the detections of self readiness for the tasks to come. Try to enjoy it, make allowances where you may have initially set walls, but most of all...enjoy the ride my friend
You are both ascending to new arenas of thought whilst the old arenas decend, become familiar with a sence of high & low mental states as you progress, the process is extremely dynamic and very specific to the individual so at best we may relate to certain things, the rest you may have trouble explaining to the ordinary Joe so be mindful of your expressions and to whom, they are there to aid with your personal development thus expect not that your local family/friends will understand what you are going through if you try to explain this seemingly irrational experience
In light, in love, with gratitude and acceptance, we give thanks to all that is, the universe, our home, our joy
-To be 'One' requires 'Two' choices, to be free is to see 'three' ways beyond the horizon-
-Words are but symbolic platforms that hold meanings, meaning has a way of building mortal towers that fall upon immortal virtues-