I know three people who have had an NDE. Two of them were fairly close friends. One was a woman who lived inthe Bavarian mountains and had a skiing accident - something with an avalanche. She was helicoptered to hospital. She could "see" the doctors operating form above and screamed at them to no, no , no, let me go, it's so beautiful here! But no-one could hear.
There was a feeling of absolute, perfect joy she had never had before and returning to the body seemed like returning to hell. However, she did return and told me the tale years later. She's a most reliable, truthful person and not in any way a wacko.
The other friend was an older man, a doctor. I don't know many of the details but he, like Thurid, spoke of an indescribable bliss and not wanting to be brought back to the body.
The third person was a younger man whom I met at a friend's party. It had happened failrly recently; he was in his 30's. He just couldn't stop talking about it. He'd had a motorbike accident and he was "dead" for a while. During that time he had the experience and it was so beautiful, so ultimate, it changed his life completely. His regul;ar life took on a new dimension. The shallowness of his previous life-style gave over to something quite different, and much more fulfilling.
I have "known" that we don't really die ever since my 13 yo cousin died from a pipe-bomb when I was 6. I saw the corpse and the whole family weeping and wailing and I knew he was still "living", though not in that corpse. I just knew.
When other people talk about "living this life to the full" I have to say I'm bit sceptical. They usually means "grab as much pleasure as you can" or "indulge yourself as much as you can" or "get drunk and screw enough women while you can" which is not what I would call living life to the full. Living life to the full, for me, was always about knowing who I really am, here and now, so that living and dying is all the same. It's a constant uphill climb and not easy but worth every step of the way.
That said, I do not want to die yet because I have responsibilities; my kids are old enough to manage without me but my husband and my mother need me. It would be especially devastating to my husband (who is ill and unable to live by himself) if I died before him and create huge problems all around, for everyone.
My advice to the OP would certainly be to continue to think hard and deep about death and what it really means, and who you really are, especially if this life is so awful. Maybe you're missing a dimension that could indeed be yours right now.