This is a hard lesson to learn. If you can learn it then your ahead of the game. I actually think that people who are more sensitive and caring feel more quilt and anxiety than others. People that wear their heart on their sleeve.
I've pinned this for those of us honest and truthful enough with ourselves that this feeling/thought that overtakes us; but, it doesn't mean we intend to "not-exist" ! All life is one day after another.