I don't know if this is the same thing but I would have existential pangs. Then I had what I thought was a near-death experience. And now I just see every day as a bonus becuse I felt I should have died in 2008.

Perhaps you can feel the same way by researching just how lucky you are to have been born in the first place? The chance of any of us actually existing is some astronomical number to 1.

But I think your problem is basically depression and anxiety, which needs to be treated. Do you have a psychiatrist?