I know you've already heard this before but you shouldn't worry too much about the AWA in my humble opinion. Its a part of the GRE and it is important but your Verbal and Quantitative are far more important and much much better (you are above the 80th percentile in both).
I wouldn't take the GRE again.. I would focus on my essays instead to strenghten my application; these essays are not only the key to transmit your story and your goals but a way in which you can show every Admissions Committee that you are more than capable of writing in English. Some people, including myself, just can't write 500 words in 30 minutes on a random topic; it doesn't mean that you are not able to express yourself in another language.