I do not meditate but regularly experience transformations of perceptionetc

So I had an awakening type experience after reading a book like 5 or so years ago. In the immediate years after I regularly lost control over my body and just kind of lay on the floor and shook (originating from my belly). Then it travelled up through my chest and into my head. I would get the same kind of impulses (which was kind of like the body suddenly tensing) as it travelled up over the course of a couple years or so. It reached my head and since then I've been having transformative feelings all over my body, during which they lightly and rapidly pulse in and out (like tensing and detensing really fast). Every time I have one of these I can feel my perception/experience shift, even if it's subtle. I've had many major perceptual shifts, sometimes I am still knocked onto the ground and can't move for a bit but largely it's these micro pulses/shakes I've talked about and some strong head tingles (warmth/vibration). 

But I've never explicitly meditated. The first 4 years or so I read a lot of literature (Zen), but the most I do recently is go for walks (short, like 10-20 mins) and that's where most of this stuff happens these days. 

What I wanted to ask is: Where would this place me in the dharma overground framework (beginner, "stream entry", etc), and where can I get started with some kind of practice? 
Just to tack on, I used to have really big transformations, that really blew me away. But I feel like I've acclimilated to it. Not that the realizations have got any smaller, but I've learned to deal with them. Before I wouldn't be able to move, but now I just kind-of space out mentally. I can't really move or talk or think but I have some level of control, and I don't get totally blown apart.
Sounds like kundalini experience.
You do not need to do formal sitting meditation explicitly to have effects, realizations and even enlightenment. Any time when you are with your thoughts and body/mind in general is a form meditation. Walking meditation is very good.

Some people are naturally wired to do self observation and once triggered will do it most of the time. Books about meditation are great trigger for them.

Still some more formalized practice would be good for you to do.
I am far from advocating full sitting meditation regime but some of it is definitely helpful to push things forward.
Can you recommend a practice? I am quite aware of energies in my body so I could push that further.