I'm sorry to hear that your karma is actually leading you to self-censor. I really feel it shouldn't. Like the writer Elizabeth Gilbert said so eloquently in her brilliant essay on writing: "Don't pre-reject yourself". Let the HN market and community evaluate what you have to say. More frequently, however, it's more likely the comment will just exponentially fall down the page, below the active fold. In real life, I constipate my self expression, even with friends. Not so much here - and it feels great - to be able to express and to semi-anonymously connect with the HN community. And the times offline I just spontaneously go up to a group of strangers and connect with them are the best. Approval seeking is the opposite of sexy. Kind of like karma seeking. And, if your karma is high enough and/or you don't care about it, it doesn't affect you. And your karma will probably increase because you truly don't care. Life lesson there - substitute with fears and confidence building.
Don't hold back - please unleash your voice. Submit stories. Sometimes you get only a few upvotes and I like to think that you were able to connect someone to something they didn't know about. And that is the power of HN. A community of connectors. Even if it's just a link, you never know where that link may end up. It could be passed along until it provides an insight, a technique, a bit of value to the end receiver.
The counterpoint. I can't tell you how many times a comment being upvoted many times has affected my mood when it's been an otherwise mundane day. Especially when I dash off a quick comment and hours later see it's been upvoted to the mesosphere. Nothing is black and white, I guess. But the point here is - the higher the karma goes, the less it matters.
http://www.elizabethgilbert.com/writing.htm