I just had a similar experience - I posted an (IMHO) well written question that was immediately downvoted with no comment. It has no answers because I suspect few people are going to look at a <0 question.

This upset me more than it should because in a vulnerable moment of need, I was digitally slapped. SO used to feel like a special gem of altruism where devs helped each other out for the love of it but now it feels like a faceless, cruel and nasty place that I want to avoid. I don't think we fully account for the emotional impact of such events when we introduce voting\karma type features.