Mbp will not boot or go into safe or recovery mode

I believe it's a 2011 MacBook Pro 15" running Mountain Lion 10.8.something. Maybe 10.8.4 or 5? It also has windows 8 on it.

Writing this on my tablet as my laptop won't load. The screen suddenly went nuts then the screen went black so I held the power button down for 15 secs to shut it down. I have to hold option down to get to boot menu since it has windows 8 on it and will automatically boot into windows first if unprompted. Windows 8 will not load at all, the screen goes black almost immediately. If I try to boot OSX the grey screen with the apple sign begins to load but then goes grey, blue, or just continues to stay in the loading screen. If I try to boot off the recovery hd 10.8.2 the screen goes blue and there are vertical lines of pink on it. I've also tried booting in safe mode or disk utility after choosing to boot from osx but it doesn't work. Not sure if I'm doing it right since it's from the boot menu. I'm at a complete loss.

I don't have any discs or usbs to boot off of because my Mac didn't come with one. Any help or advice would be greatly appreciated.

Edit: I don't know if this is relevant information but I tried to download maverick the other day but paused the download. Not sure if it finished downloading or if I even tried to install. Honestly, I was flying on autopilot and didn't even look at what it was. Had no idea it was an os upgrade. Yes, I am that clueless.... Not sure if this is related/caused my current woes.