Guild Wars 2

I really need help with this when ever I am playing GW2 I will randomly get a black screen but I can still hear the music, and I am forced to close GW2 and re-launch it, it sometimes happens within 2 minutes of playing and sometimes within 15 minutes, I really want to fix this issue and have look at a lot of ways to possibly fix this and none of them have worked, I have tried downloading the Microsoft updates, updating to the latest drivers, and plenty of other little fixes, like turning down my graphic settings, turning vsync on etc.. I run the game with medium settings most of the time and get around 60 fps, my graphics card is a AMd ASUS HD 7670 series, my processor is a AMD FX™ – 8120 eight core processor 3.10 ghz, please someone help.

I have tried deleteing the cache folder and it did not work, im not sure how to do the other two things you suggested though, something I also forgot to mention was that I used to play guild wars 2 a couple months ago and I did not have this issue, but now when I want to start playing gw2 again im getting the black screen randomly.