Q: I'm having trouble logging in and when I do the screen becomes distorted any ideas?

The other day I was playing a game on steam (civ v) when all the colors on my screen seemed to be inverted except for letters. After waiting about 30 minutes I did a forced shutdown by holding the power button and then attempted to start it back up. It made it just past the first loading bar but then got stuck on a white screen. I looked online and found safe start so I tried it and it worked great. Following the advice, I tried rebooting it again without safe start and the white screen happened again. Then I started it in safe start and went into system preferences to users to login Windows (I think) and made a list and removed everything there. I tried to boot it up again it didn't work so I went on safe start and used disk Doctor to do first aid. I tried logging on without safe start again and managged to log on but within seconds the screen became distorted again with the disk Doctor page missing chunks and random lines and blocks of random pixels and after a minute it froze. again.