Backstory 
Between April 2018 and January 2020 I had one 20 minutes session 6-7 times a week, practiced anapana and silent noting. I had Goenka retreat in June 2019. Now I am having two 30 minutes sessions each day since the 31st of January this year.  
In February I practiced concentration on the breath as described in TMI, since the 8th of March I am doing noting aloud. When I note the breath, noting interferes with it. 
On the 23rd of March I understood on the level of experience that the unpleasantness of the sensation is not the quality of the sensation – it is generated by mind. Since then some kriyas and wild (desire to burst in all directions, shout, and fly away) fantasies started to happen. Several sessions had 4-5 distinct phases, and body shaking took place only once per session.  
On the 29th of March I discovered that the object and the knowing of it are different things. I distinctly notice the feeling and the recognition of it. For more details see my log.  

The session itself (evening session 30 March 2020) 
I started getting powerful kriyas while taking a shower. I was reflecting on the nature of subjective experience, suddenly a thought appeared “I am thought and you are not thinking me – I am thinking myself, ha-ha”, and then boom – I started fiercely shaking. I was dis-embedded from the thoughts. This experience is rather familiar for me – I’ve had it several times during this month (in the forest, in the institute, and during meditation sessions), but not that strong. 
The session went as if I was possessed with a demon or had an epileptic seizure. I could not stand, because the body was shaking and moving, so I took a sit. There is a mirror in my room and I saw myself there several times – there was a grimace of madness and fear on my face. I could not note aloud, too, because the sense of someone doing the meditation has vanished. I almost did not hit myself (one arm tried, but another arm stopped it). After a while the body got exhausted, and there was a period of relative calmness. Although after a while I started spitting saliva on my clothes (I have no idea why I did this). Basically the whole meditation was one big kriya for 30 minutes, however, I am not exactly sure I am using this term correctly. I was detached from my thoughts. I could hear them speaking to each other and using the word “I”, but it was clear there was no one they were referring to. When they did this, that funny man from this well-known video Risitas - Las Paelleras  appeared in my imagination and laughed.  

Today (31 March 2020) I decided to heal myself a bit after an insane session yesterday evening.  I recited the verse May I be filled with loving-kindness May I be peaceful and at ease May I be happy May I be well 
The feeling of loving-kindness itself almost did not arise, I just got calmer and able to do something. Before the loving-kindness I still wanted to shake, now I feel like a normal person again.  

My Questions 
What is going on, why am I having this? Is it A&P territory? Is it dangerous? Can I go insane? Should I move to a more wet technique, or keep doing noting? How to deal with this wild crazy stuff?

I am no doctor and no psychologist, so don't take my word for it, but it sounds to me like you are having dissociative seizures, also called psychogene non-epilectic seizures. I have had those. They aren't dangerous in themselves, but an indication of trauma. Maybe you are going to fast with your practice? Give yourself a chance to integrate stuff, please, and don't fry yourself! If loving kindness works for you, maybe continue with that and let that be your only practice for a while. A while back (a year ago?) I was recommended to make all parts of me feel safe to express their worries and sort of wait up for them. That was some powerful stuff. Don't underestimate loving kindness. 

You certainly don't need those body jerks. I had that too and these jerks would go on and on.  Kenneth Folk told me to "just decide that you don't want those body jerks anymore, and test and ask them to come up and see if they do. If they do you decide that you don't want body jerks any more". Worked like charm for me. 

I don't know much about Loving Kindness but I did practice Self-Reiki prior to discovering Buddhism 11 years ago. Maybe me placing my "healing" palms all over my body developed self-acceptance. Maybe. It certainly didn't harm me. 

Also, these body jerks can be a sign of restlessness. Slow down. Instead of desiring to Note Aloud both in and out breath, note aloud only one of them. For example note aloud the outbreath (better note sensation associated with it like abdomen falling) and then note silent when breathing in (note Coolness in the nostrils or abdomen raising). 

Shinzen suggests to use "the voice" to invoke certain amount of Equanimity. Use a calm and soft voice when noting aloud to get into a calm and relaxed state. This is not a race but cuddling up with This-ness  

Hi Mikhail, 

Kriyas, shaking and involuntary movements like you describe are common at certain stages of the path. They can sometimes be strong depending on one's own past conditioning.There's nothing wrong or dangerous with them coming up, they are good things to witness and notice curiously. 

I like some of the suggestions in the posts above about being gentle and kind in your practice, slowing down a bit and trying out more somatic-based metta practices. There's no one right way to go through this territory, approach different techniques with an experimental attitude and notice what happens, what works for you, and what doesn't. 

This thread could perhaps be of interest? Sorry, I don't know how to shorten the link.

https://www.dharmaoverground.org/discussion/-/message_boards/message/17029857?_19_redirect=https%3A%2F%2Fwww.dharmaoverground.org%2Fdiscussion%2F-%2Fmessage_boards%2Fsearch%3F_19_redirect%3Dhttps%253A%252F%252Fwww.dharmaoverground.org%252Fdiscussion%252F-%252Fmessage_boards%252Frecent-posts%26_19_keywords%3DPsychogenic%26_19_formDate%3D1585675815394%26_19_breadcrumbsCategoryId%3D0%26_19_searchCategoryId%3D0#_19_message_17029857

Write a short text as the title for your link, then select all that text, then click on the "Link" menu button in the top section of editor. It should open the dialog for entering the URL. Then enter the URL and click Ok.

A Shorter Link Title

Thanks! I hope I'll either remember that the next time or be able to find it again. 

It should not be a problem. The only thing that you need to do, is to phrase what you are looking for, clearly, for a specific platform, and let Google find it for you. e.g. ...Set title for a hyperlink liferay forum editor... .

Now you only have to remember liferay forum editor!

Hahaha, exactly! That and "hyperlink" and "set title" I think I'd rather take my chances of remembering that the instruction was given in a thread in which I wanted to link back to my thread about psychogenic non-epileptic seizures. So now I only have to search for that on this forum, and then this thread will pop up among the resarch results. I'm an expert on finding stuff the less fashionable associative way. 

Thank you for your reply. My noting practice is not calm and peaceful now, for sure. When I note the sensations, I also notice many more sensations that remain unnoted - is this normal? The goal is not to note as many as possible, is it?

These body jerks often accompany a profound change in self-perception, when the mechanism of attributing my thoughts to "me" abruptly stops working. So I probably need to learn to make this change more gentle and observe it with more equanimity.

Thank you for your attention. How long should I do the technique before moving to another, how frequently should I experiment? I started doing noting aloud only 3.5 weeks ago - is it ok to switch to something different? Is it ok to do different kinds of meditation simultaneously?

What do you mean by somatic-based? I am not familiar with this term in relation with meditation. What are other examples of somatic-based approaches?

Thank you, this sounds pretty similar to what I am experiencing. I also remember having them several years ago during my period of depression, and at that time they were caused by trauma, tiredness and overall low mood level.
What happens now also resonates with what you wrote - I feel sudden lack of feeling someone, and there is some sort of shock and panic in the body and mind because there are parts that cling for identification.
I will be more gentle with myself. My life is reasonably good now, but I feel that I have to deal with my loneliness, tiredness and detachment - maybe they are showing up.

Yes it's very normal to start Noticing more sensations while Noting only one As you start progressing through stages of insight the speed of noticing will increase. Or decrease at times. All good. 

Whenever you get into very difficult situation try and notice if it's based on a Mind State. Note it. Then you can Always retreat back into noting Body sensations. They are much easier to cope with and Insight is Insight no matter if you are noticing a mind state or body sensation. Choose your battles wisely  

Jerks, body stiffness and pains are sure signs of the early stages 1 to 3. Our memories of certain situations also (stage 2). 

Noting at least 1-2 sensations a second is still a good thing to do + Noticing extra sensations while Noting is fine as things do start speeding up in 3 C's stage (3rd stage of insight). 

Acceptance of what is and applied Effort in noting matter of fact will aid in passing these stages. 

When off cushion be gentle to yourself and even do some hobby. When on cushion then apply Effort, matter of fact noting/noticing and Acceptance. 
Try not to fall into conceptual contemplation of mind states during the practice. Instead Label that very state as Thinking, Wondering, Guessing etc ... All mental states and all body sensation = one word label, nothing more. One after the other; tap, tap, tap, tap ...  

Once off cushion then do the conceptual pondering