Are you (perhaps a rather bleak take on)
Am I a plague, a curse, a sin?
This could be a reference to the inherent evil nature of some people.
I don't even know where I begin.
Unless I missed something, we aren't 100% sure where or how (human) life started.
Some parts of me love, some parts of me hate.
Some people are nice/loving, some people are evil/hateful.
But I'm pretty sure Mother doesn't think I am great.
Not sure on this one, perhaps "Mother" as in mother earth, and "doesn't think I am great" could be a reference to pollution and/or the use of natural resources?
Viewed as a virus, they say I will never die out.
Although lately I am filled with much doubt.
And here's where I become really unsure, but perhaps this could mean some people say it's too late to reverse humanity's negative effects on the earth..? Eh.
Oh, and for the title:
Lots of people currently living, and every day people die.