Who said anything about individual visual perception?
I mentioned it at least a couple of times with the chair example, and the kid being murdered example.
What we perceive with our senses can be corroborated by different means.
No. It can only be corroborated via the senses.
What does this say about "intuition"?
just the same, intuitions can only be corroborated by other intuitions, your own or those of other people
My life has meaning to me.
subjective meaning, which, absent of a link to objective meaning, is literally meaningless.
ETA: And you have no business telling me what to do with my own life.

how was I doing that?
Darwinism is a scientific theory that doesn't have anything to do with morals or ideology. Heck, it doesn't even have anything to do with atheism per se.
It's the founding principle of a whole world view, the evolutionary paradigm. It's everywhere in education, academia and the media. When it attempted to assert itself in the field of morality it was several more times disastrous than any religious abuses in the past. So gladly we have now (been forced to) returned back to theistic morality, even if it is not explicitly named that way by those involved.
It's now called Universal Human Rights. Of course no empirical evidence can support these rights; it's a spiritual view of man, rather than an exclusive materialist one.
ETA: and btw, the theory of evolution helped a great deal in the advance of science and medicine.
how?
What about the Inquisition, the Crusades, and Islamic terrorism? You're not going to convince me that religion is the way to go, it has quite a crappy track record.
yes, people get things wrong. But when the spiritual view of man was subtracted from morality people got things several times more wrong.