Why do I still consider myself an optimist?

Tolstoy once referred to the realization of one's mortality as an "arrest of life."

I take great comfort in Tolstoy because, although he had no more answers than me, reading his thoughts is akin to reading a more philosophically elegant version of my own.

The phrase "arrest of life" perfectly captures the physical and emotional agony of experiencing my own mortality. My mortality hits me repeatedly throughout the day, every day...in the shower, sitting in class, whatever I may be doing. I can't stop it and I can't anticipate it, but when it hits it truly is an arrest. I feel as though life and time both stop for an instant and my mind reels in panic. Usually I instinctively touch my face, which I know is a gesture of helplessness. I'm reassuring myself that I'm still here, knowing all the while that it is futile because one day I will not be here. The first words that come to mind when I've regained hold of myself are usually, "Oh, God," or "Oh, fuck." The frustration and the inevitability are all but unbearable. Some philosophers argue that, upon realizing the futility of life, the only option is suicide.
I can't fathom that. The desperation drives me to cling to life.

I realized earlier today that I will never die and never experience death, in the sense that upon dying, I have been annihilated and it is therefore not something I will ever
experience or know. Certainly, I've read that before, but never today I actually felt it and took temporary comfort in the fact...but nonetheless, I still want to continue to exist! I want to continue to exist in some form or another and I try to rationalize it but I can't. There is no rational reason aside from existing for existence's sake. An unjustifiable attachment to my consciousness.

I ponder the alternatives. Immortality on earth is not appealing. I imagine that earth would become truly unbearable after a few hundred or thousand years. My Meaning of Life professor doesn't see why that is necessarily the case, but I can see it happening. So I ponder eternal nonphysical life after death. This could be desirable, assuming it opens me up to a sort of wisdom and existence in world utterly unfathomable by the corporeal mind, where time does not exist. However, because I can't truly think about what such an existence would entail, I can find little comfort in it. It seems, then, that I should welcome the end provided by death, but I do not.

Taoism offers some hope of internal peace. They say that in learning the Tao, one loses her fear of death. Death no longer matters because one has tapped into the one, the whole. Consciousness is insignificant and fundamentally nonexistent. All there is is the whole. It sounds trippy, but is really sort of a fantastic notion. I need to delve deeper into it, and explain more at some point.

There's always so much that needs to be explained, and never the time.

I need to chase these thoughts away so that I can go study...including the thought that all the studying in the world is done in futility.

How is it that I'm so haunted and yet still an optimist and still happy?
How do I still find so much beauty and joy in a life that often feels like little more than a cosmic joke?