I think I understand you. If you remove the "safety net" of self termination, that leaves...a big nothing. IMO it's natural to have a fear of the unknown future, even if it looks positive.
I think it's also natural to have a fear of aging and not knowing what or who will be there if the worst happens. I recently took steps about this issue myself. (Taking care of my future, not sui.) I want to live. I want to be part of my family and friends futures. I want to watch all of my grandkids and future grandkids grow up. I don't mind suffering a little and having normal life stresses, but...sometimes.........the future seems like something I don't want to stick around for.