How is being scientific at all comparable to nihilism, such that you ceded that point in your head?
Heh, this is a bit like that moment when you explain null vs empty/zero values to a junior programmer. :-)
You seem to be falling victim to the misapprehension that lacking belief is the same as nihilism. But nihilism actually requires a degree of belief in order to be fully achieved. It's the active rejection of religion and morality. In other words, you kind of have to believe that there is nothing. (Absence of evidence vs evidence of absence, and all that....)
Failure to believe in anything is a workable modus vivendi that doesn't imply the explicit rejection of morality. It simply posits that there are no articles of dogma, while accepting that the best available evidence is thus and so... until new evidence arises.
Failure to believe doesn't lead inevitably to despair. It may give rise to constitutional skepticism, but that in itself doesn't have to become unhealthy or drown one in nullity. I experience wonder, poetry, rapture when I hear good music and see good art. I embrace absurdity and humour. I love food, many flavours and smells. I also experience a constant sense of novelty because I have very little certainty about how each day will turn out. The mere possibility of alternatives is often enough to keep boredom and depression away.
Nihilism rejects purpose, meaning and ultimately, hope. It's a nearly impossible condition for most human beings. Failure to believe can likewise be quite upsetting, because it humbles you utterly if you really allow yourself to experience it. I expect it's part of the release that the Buddha talked about. But there's a perverse intensity to the joy that you feel when you're laughing in the face of the void.