Existential Crisis - Why Do I Blog?

Why do I blog? Why must this blog exist when there are millions already out there that are similarly rambling? Why must I anonymously post about myself online when the audience is satiated? Will I really be making a difference to someone's life? I don't think so...I barely have a readership (the thought consumes me so!)
If I continue along the same line of thinking, I could easily end up persuading myself to shut down this blog.
And subsequently, cease to try living...("Huh?" You wonder, "What did she just say?" Go on...read it again...I meant every word.)
After all, by the same logic as above, why must I breathe or eat or sleep when there are millions out there similarly breathing, eating and sleeping? Why must I read, study, work or use the Internet when there are millions out there that can do the same...? With every additional minute I take up on earth, I'm using up the earth's resources and were I to refuse to do so they would be split among the remaining human beings, who are barely distinguishable from me. I do not possess extraordinary ability; my absence from earth would not be noticed and my work could easily be replicated by another person (provided they are given similar education, etc.). The natural question arises...should I even be living?
Alas this analogy between blogging and living has heated up my mind so potently that I now guard my blog like I would my life.
I blog, therefore I exist.
Hence, I must blog.