Why is such a miserable person so invincible?

To me it definitely seems that the people who suffer and have all this sadness/anger/bitterness inside, and want to die, live until old age while the people who want to live and have the most positive attitudes about life always end up dying too soon. I know because I've tried to kill myself twice and both attempts failed miserably and I feel miserable about life in general....and you know what I'll be the one that will live until I'm in my 90s even though I hate life and feel pain in living. Life just makes no sense so I've decided to try and act like I enjoy life as much as possible and maybe I'll get lucky and I'll get to die sooner.