Well, I have some things I consider straightforward and clear answers, some guesses, and some aspects I don't have any great guesses on at all.
I will begin with the things I consider easy: The heat, movements, energy, and the Kundalini stuff, as well as the hyper-sexuality: at least some part of that is clearly the stage of the Arising and Passing away, aka 4th insight stage, aka 2nd vipassana jhana. It is common, comes and goes, gets more intense with practice, lets off with less practice, at least for most people.
There are aspects of the way you describe how little sleep you got and how jacked-up you were that remind me of a manic episode. Here's the problem: manic episodes and the A&P can overlap and look a lot alike. Here is my brief blurb on that:
Bipolar Disorder and The Stages of InsightI wasn't there, am writing at a distance, have never met you, and so any clear sorting of this is beyond my abilities, but some part of this is clearly explanatory to some degree, I feel.
As to any meditation practice freaking people out: all of them can do it. The more mental the practice, such as imagining a mantra or an image, the more likely you are to freak out, but even extremely physical practices can at times cause similar problems, so it is more shades of grey than absolutes. I agree that physical practices, such as meditation on the breath and yoga with a high degree of mindfulness of the position of the body and the breath are likely to be more helpful than things where you use a mentally created object. This is just an educated guess, and you will have to do the experiment for yourself.
You definitely need a good meditation teacher who has had Kundalini stuff happen to them and who can actually know you and get a sense of you on the ground where you are in person. I can't imagine there isn't one in Italy somewhere: keep looking. They must be there. I would beware of those who just try to get you to pay and won't help you with straightforward information. I can't be sure they don't know what they are doing, but something in that does tend to raise my red-flags. This may be my own bias.
What do you do in the rest of your life? Are you working? What do you do with your mind all day long?
Things to do about Kundalini stuff: plenty of people here have gotten something out of the AYP stuff: might contact some of them and ask them their thoughts on it. Search on threads for AYP and see what you get. Energetic practices are a mixed blessing: they can both clean and clear out energy channels and also cause some real energetic craziness. Chuck Kasmire is a grounded guy who has done a lot of those practices and might be a good person to contact: try the Messaging tab above and wait a long time after each click, as it is REALLY slow, like you can't believe-how-slow slow.
Heavy foods tend to help when it is at its worst. Orgasms can unload some energy. Heavy physical work and exercise (done safely and without hurting yourself) can help ground things down. This is standard advice. Try to sleep every night even if you don't feel you need to. Definitely eat 3 meals a day even if you don't feel hungry: lack of sleep and food is a quick ticket to crazy-land for many people: avoid this if you are prone to more extreme effects. When practicing, work to just settle in, to keep the energy calm and to train the mind to that first. Work on other things later, as it sounds like that basic, settled, clear aspect is not well-developed. Gently reign things in. My teacher Bill Hamilton would practice this way, spending hours just settling the mind, calming it down, gently restraining it until it was stable, well-behaved and able to then proceed with less trouble.
Consider a trip to Asia to talk with a senior meditation teacher about this, someone who has trained thousands of people, one of the big dogs, such as a senior Mahasi-style teacher, and see what they say. Their experience with handling this sort of thing will be vastly beyond most of what you will find elsewhere.
Those are my initial thoughts. You need someone who can actually get to know you as a live person who knows this territory. It sounds like you are looking for them and haven't found them yet. They are out there. This stuff is somewhat rare but definitely not unheard of. You might also contact Dr Willoughby Britton at Cheetah House. She studies the dark side of meditation and may have some contact information and suggestions.
Cheetah House