I had a similar experience to you on a pretty large dose of IV 5meo HCl. I don't think we are necessarily talking about the experience as much the aftermath, so I'll spare details, but it was a "classic nde". I felt all that I am, all that is me-everything stripped away like so much dirty laundry. At the end of "the tunnel" was a void, empty and completley black, but not dark, full of light just vast and empty. I give it fanciful names like "Shining blackness/void/dark". Except it was anything but empty, it shined with brilliant clear light. I saw it to be a huge field of potential, all things that were, is, and are to be existing in unmanifest formless potential. And stripped of all my be-ing, "I" too was set to dissolve utterly into it, until implored by some voice-not-voice-to-the-inexistent-"I" to "REMEMBER!!!" upon which I recalled living, and returned to my face-down body in a crap apt on a spinning rock in vast space.
I had a discussion with a good friend recently in which we argued our relative stance on the afterlife. We used metaphors, mine involving an individual life as a raindrop in a shower falling over the ocean, once that drop hits, it is no more, utterly dissolved molecule by molecule into the vast void of the sea. Eventually, all of that drop will again evaporate and again descend as rain, but no drop contains the constituency of the first one. Once we are gone, we are gone, not to incarnate again.
For me, this was scary at first and my self importance railed against it. Now, however I find it liberating.
I don't like actually using the term incarnation as it implies a re-incarnation, although I do think it fits, as what I returned with is the knowledge that I emerge from the create-ing and do so only to feel the creation in proxy for the create-ing (not a creator) because it cannot do so, being as it is eternal, infinite, outside space and time and formless. Life is a bestowal which emerges from the mind of creation. Kabbalist thought informs some of this, just so you know.
Something resonated in my head when I came back from that trip, a cryptic quote that nonetheless made all the sense to me:
"You are born, lain upon the cold dead breast of your Mother, your Father stands far off."Death is a good thing to practice.
I picked my name here from that. The only reason 24 is after it is because I immediately forgot the password for null's account.
I have another story, that I might relate later, in which a friend "died" in hospital after ingesting LSD in an orange microdot. Supposedly the doctors somehow determined that he had been poisoned with cyanide (in a "death pill"?!?!?). He did however have the whole tunnel deal too, but came to three entities within the light, one of whom asked him "Hey! (name)! Who do you love?" When he stuttered that he did not know, he was punched in the chest and returned to his body, the defib paddles just then being lifted off his chest. His experience was transformative, as was mine.
I hope you have wellness in body mind and spirit, and whatever difficulties you have pass soon. Even if comfortable with death, none of us know it, and I don't know how to be free of fear entirely. I am sorry to hear about your health scare, be good to you.
Sine experientia nihil sufficienter sciri potest -Roger Bacon
*γνῶθι σεαυτόν*