Hey there, to answer your question I looked over your blog for a moment. I noticed several comments from cheetah, which is a bot that comments if what you posted traced back to another site through google. Typically cheetah will detect a copy/paste or link to something that doesn't belong to you. In addition there are several bots that down vote things considered to be plagiarism. The only thing that will decrease your reputation are down votes. If you have decreased in reputation from 38 to 18 you have received a large amount of down votes. people will down vote for the reasons I have mentioned, and for improper tagging. For example, this isn't a post introducing yourself so a bot or user may down vote for spam tagging. Hope this helps :)