18 percentile

I always knew that I lack something in writing skills. Though I knew qualitatively that I was bad, but recently I received a quantitative figure. In the analytical portion of GRE test I received 18 percentile (3.5 score). Wow, so I am much below average in writing skills, still I have been shamelessly writing blogs and advertising them and thus flaunting by poor writing skills. So reader, please, if have some more time left after reading all this non-sense please point out some mistakes and suggest some improvements. There is 82 percent probability that you have better writing skills than me.