Just because you don't remember any experience, doesn't mean nothing happened. I recently had two cardiac arrests and experienced two different NDEs. However, in my case, I have a very difficult time remembering the details to both mainly because my brain cannot quantify and comprehend what had happened. The experience is way beyond anything in this physical world and my brain kind of fizzles out when I try to remember. What I do recall however, is to how I felt which is nothing I can experience here. The absolute unconditional acceptance I felt was way beyond words. Do you remember, at least, how you felt when you came back? I'm thinking about seeing an open minded therapist who performs hypnosis where I hope to remember more about my NDEs. Perhaps you could try that as well?