What didn't help is that you posted it as 'self post', so one without a link (those are penalized).
Better to wait until 8:30 tomorrow morning, post it as a linked article and put your explanatory text in the first comment.
I put a lot of work into this site and to have it only get 3 comments and 2 points was kind of a let down, and also kind of confusing.
The 'self' presumably refers to the article being HN only.
To avoid meta-discussion and 'Ask HN' style posts clogging up the new page they are penalized, so they'll typically drop off faster even if they do receive a lot of votes. And if they don't receive a lot of votes then they're gone even faster.
So if you want your 'rate my startup' post to be seen best just post the link, and add any extra info as the first comment in the thread.