So recently, after playing a mm game on nuke, my game crashed and I had to quit out. Every time I try to boot the game back up the opening credits will roll, but they are always very grainy, like you might see on an old tv, and there are green blue and red dots everywhere. When the game reaches the main menu the game goes completely black, and while I can still hear the music and the mouse noises when I go over the icons in the main menu, I can't see anything. I then have to close the game and it gives me the error message "application csgo.exe has been blocked from accessing graphics hardware". I've looked everywhere but can't seem to solve the problem. Please help!

I updated the gpu drivers (NVidia GeForce 840m) and also rebooted