Life, Death and the Time Between

Very often, I contemplate the fragility that is life. We are born into this world, as if we are dying, when merely it is the gateway in, then experience the trials, tribulations and triumphs of life, uncertain of when the ending hour will arrive and so... we live. Day to day... uncertain and in doubt. Mortality is a frightening thing.
I understand why it is unhealthy to think about death. Dying. The end. Yet, what about thinking about it, for the sake of fulfilling my time now? To do all I can, with the means I was given, in the situations presented before me? Is that... wrong?
When these thoughts... sneak into my head, I suddenly feel so small... so weak... so unprepared and so incapable in grasping all the achievements and self satisfying growth experiences that I long for...
I wish these thoughts would... subside. As I am not the one calling the shots, controlling the pieces, I can only... try my best. Yet sometimes... It isn't enough.
I feel so... lost right now...
Hmmm....