A special dream state where you can experience ego death?

[XYZ]

There is a unworldly type of dream state I've entered, which is totally freaky. This has only ever happened when I woke up after 5 hours or so, feel very tired still and then take a morning nap. Doesn't last long, and I have a feeling that it's an effect of being sleep deprived and my brain trying to squeeze out as deep a sleep as it can in the last moments of a nap. 

It has happened without taking any sleep aids before the morning nap, or after taking more melatonin or other herbal supplements. I used to feel very frustrated when woken up too early and still very tired, but now that I've correlated morning naps with this phenomenon, I just take something if I need to, and look forward to possibly experiencing this again:

Unlike during normal sleep, this type of dream state has extremely vivid physical sensations, which I feel deep in my body, even after waking up, so it feels like these are 'real' and it wasn't just a dream. I've experienced things such as spinning, floating,flying, falling, being shaken violently, and other motions. The scariest was when I dreamed I was walking down a street, then suddenly turned around and launched a mile up into the air, afraid I was going to crash down to Earth and splatter. That woke me up and my sides had tensed up and the same feeling remained, as if that had actually just happened to me.

One more important characteristic of these very-tired-morning-nap dreams is there is a deep vibration I feel all throughout my body. I could only describe it as cosmic energy, and the most physically pleasurable sensation I've ever felt. I tried to hold onto it at it's peak, but then I wake up, still in it's afterglow, and am incredibly relaxed and happy, not matter how tired I may still me.

Now here is the experience I had several months ago. During the dream, I found myself sitting in a chair in a nondescript office waiting room, and I started to meditate. This cosmic vibration swept over me and enveloped me, and this time I felt it more deeply than ever before or since, the best physical sensation ever. And as it became more intense and overwhelming in a good way, I started to feel the sense of "me" disintegrate and radiate in all directions as I was literally disappearing. I felt like I was going to literally die, got scared and fought against it, not letting myself vanish, and then what was left of my sense of self turned sideways and I found myself lying in bed, basking in the afterglow, yet frustrated that I couldn't surrender to ego death. 

I've though about this experience many times since, hoped to recreate it, and was reminded again today when I went really deep in a kundalini yoga class. This was before watching Leo's full ego death experience on @C-B and more recent videos from this year. I feel that with gaining more theoretical foundation and secondhand knowledge since then, that the next time this happens, I could allow myself to fully surrender to ego death and finally have more direct experience of no-self.

So I am wondering, has anyone experienced something like this before, have been able to enter such a state with conscious meditation or know more about what causes this state to occur? Also cannot be certain the next opportunity will be taken, since I think I understand now ego death feels like you are actually physically dying, and the body goes into overdrive trying to keep the "you" alive.

[XYZ]

It's not guaranteed to happen every time I take a morning nap, I took one today after 6 hours sleep, and just regular dream states occurred. I think I have to be very super tired for that to happen, but I'm hoping to find some other way of accessing this state.

Maybe if I can understand what happens from a neuroscience perspective then it can be created by other means. I don't have access to psychedelic substances, so this is the closest I can get for now. I'll be meditating on that cosmic vibration, which might make it more accessible while sleeping.